    // @tag foundation,core
    // @require ../lang/Date.js
    // @define Ext.Base

    /**
     * @author Jacky Nguyen <jacky@sencha.com>
     * @docauthor Jacky Nguyen <jacky@sencha.com>
     * @class Ext.Base
     *
     * The root of all classes created with {@link Ext#define}.
     *
     * Ext.Base is the building block of all Ext classes. All classes in Ext inherit from Ext.Base.
     * All prototype and static members of this class are inherited by all other classes.
     */
    (function(flexSetter) {

    var noArgs = [],
        Base = function(){},
        hookFunctionFactory = function(hookFunction, underriddenFunction, methodName, owningClass) {
            var result = function() {
                var result = this.callParent(arguments);
                hookFunction.apply(this, arguments);
                return result;
            };
            result.$name = methodName;
            result.$owner = owningClass;
            if (underriddenFunction) {
                result.$previous = underriddenFunction.$previous;
                underriddenFunction.$previous = result;
            }
            return result;
        };

        // These static properties will be copied to every newly created class with {@link Ext#define}
        Ext.apply(Base, {
            $className: 'Ext.Base',

            $isClass: true,

            /**
             * Create a new instance of this Class.
             *
             *     Ext.define('My.cool.Class', {
             *         ...
             *     });
             *
             *     My.cool.Class.create({
             *         someConfig: true
             *     });
             *
             * All parameters are passed to the constructor of the class.
             *
             * @return {Object} the created instance.
             * @static
             * @inheritable
             */
            create: function() {
                return Ext.create.apply(Ext, [this].concat(Array.prototype.slice.call(arguments, 0)));
            },

            /**
             * @private
             * @static
             * @inheritable
             * @param config
             */
            extend: function(parent) {
                var parentPrototype = parent.prototype,
                    basePrototype, prototype, i, ln, name, statics;

                prototype = this.prototype = Ext.Object.chain(parentPrototype);
                prototype.self = this;

                this.superclass = prototype.superclass = parentPrototype;

                if (!parent.$isClass) {
                    basePrototype = Ext.Base.prototype;

                    for (i in basePrototype) {
                        if (i in prototype) {
                            prototype[i] = basePrototype[i];
                        }
                    }
                }

                //<feature classSystem.inheritableStatics>
                // Statics inheritance
                statics = parentPrototype.$inheritableStatics;

                if (statics) {
                    for (i = 0,ln = statics.length; i < ln; i++) {
                        name = statics[i];

                        if (!this.hasOwnProperty(name)) {
                            this[name] = parent[name];
                        }
                    }
                }
                //</feature>

                if (parent.$onExtended) {
                    this.$onExtended = parent.$onExtended.slice();
                }

                //<feature classSystem.config>
                prototype.config = new prototype.configClass();
                prototype.initConfigList = prototype.initConfigList.slice();
                prototype.initConfigMap = Ext.clone(prototype.initConfigMap);
                prototype.configMap = Ext.Object.chain(prototype.configMap);
                //</feature>
            },

            /**
             * @private
             * @static
             * @inheritable
             */
            $onExtended: [],

            /**
             * @private
             * @static
             * @inheritable
             */
            triggerExtended: function() {
                //<debug>
                Ext.classSystemMonitor && Ext.classSystemMonitor(this, 'Ext.Base#triggerExtended', arguments);
                //</debug>

                var callbacks = this.$onExtended,
                    ln = callbacks.length,
                    i, callback;

                if (ln > 0) {
                    for (i = 0; i < ln; i++) {
                        callback = callbacks[i];
                        callback.fn.apply(callback.scope || this, arguments);
                    }
                }
            },

            /**
             * @private
             * @static
             * @inheritable
             */
            onExtended: function(fn, scope) {
                this.$onExtended.push({
                    fn: fn,
                    scope: scope
                });

                return this;
            },

            /**
             * @private
             * @static
             * @inheritable
             * @param config
             */
            addConfig: function(config, fullMerge) {
                var prototype = this.prototype,
                    configNameCache = Ext.Class.configNameCache,
                    hasConfig = prototype.configMap,
                    initConfigList = prototype.initConfigList,
                    initConfigMap = prototype.initConfigMap,
                    defaultConfig = prototype.config,
                    initializedName, name, value;

                for (name in config) {
                    if (config.hasOwnProperty(name)) {
                        if (!hasConfig[name]) {
                            hasConfig[name] = true;
                        }

                        value = config[name];

                        initializedName = configNameCache[name].initialized;

                        if (!initConfigMap[name] && value !== null && !prototype[initializedName]) {
                            initConfigMap[name] = true;
                            initConfigList.push(name);
                        }
                    }
                }

                if (fullMerge) {
                    Ext.merge(defaultConfig, config);
                }
                else {
                    Ext.mergeIf(defaultConfig, config);
                }

                prototype.configClass = Ext.Object.classify(defaultConfig);
            },

            /**
             * Add / override static properties of this class.
             *
             *     Ext.define('My.cool.Class', {
             *         ...
             *     });
             *
             *     My.cool.Class.addStatics({
             *         someProperty: 'someValue',      // My.cool.Class.someProperty = 'someValue'
             *         method1: function() { ... },    // My.cool.Class.method1 = function() { ... };
             *         method2: function() { ... }     // My.cool.Class.method2 = function() { ... };
             *     });
             *
             * @param {Object} members
             * @return {Ext.Base} this
             * @static
             * @inheritable
             */
            addStatics: function(members) {
                var member, name;

                for (name in members) {
                    if (members.hasOwnProperty(name)) {
                        member = members[name];
                        if (typeof member == 'function' && !member.$isClass && member !== Ext.emptyFn && member !== Ext.identityFn) {
                            member.$owner = this;
                            member.$name = name;
                            //<debug>
                            member.displayName = Ext.getClassName(this) + '.' + name;
                            //</debug>
                        }
                        this[name] = member;
                    }
                }

                return this;
            },

            /**
             * @private
             * @static
             * @inheritable
             * @param {Object} members
             */
            addInheritableStatics: function(members) {
                var inheritableStatics,
                    hasInheritableStatics,
                    prototype = this.prototype,
                    name, member;

                inheritableStatics = prototype.$inheritableStatics;
                hasInheritableStatics = prototype.$hasInheritableStatics;

                if (!inheritableStatics) {
                    inheritableStatics = prototype.$inheritableStatics = [];
                    hasInheritableStatics = prototype.$hasInheritableStatics = {};
                }

                for (name in members) {
                    if (members.hasOwnProperty(name)) {
                        member = members[name];
                        //<debug>
                        if (typeof member == 'function') {
                            member.displayName = Ext.getClassName(this) + '.' + name;
                        }
                        //</debug>
                        this[name] = member;

                        if (!hasInheritableStatics[name]) {
                            hasInheritableStatics[name] = true;
                            inheritableStatics.push(name);
                        }
                    }
                }

                return this;
            },

            /**
             * Add methods / properties to the prototype of this class.
             *
             *     Ext.define('My.awesome.Cat', {
             *         constructor: function() {
             *             ...
             *         }
             *     });
             *
             *      My.awesome.Cat.addMembers({
             *          meow: function() {
             *             alert('Meowww...');
             *          }
             *      });
             *
             *      var kitty = new My.awesome.Cat;
             *      kitty.meow();
             *
             * @param {Object} members
             * @static
             * @inheritable
             */
            addMembers: function(members) {
                var prototype = this.prototype,
                    enumerables = Ext.enumerables,
                    names = [],
                    i, ln, name, member;

                for (name in members) {
                    names.push(name);
                }

                if (enumerables) {
                    names.push.apply(names, enumerables);
                }

                for (i = 0,ln = names.length; i < ln; i++) {
                    name = names[i];

                    if (members.hasOwnProperty(name)) {
                        member = members[name];

                        if (typeof member == 'function' && !member.$isClass && member !== Ext.emptyFn && member !== Ext.identityFn) {
                            member.$owner = this;
                            member.$name = name;
                            //<debug>
                            member.displayName = (this.$className || '') + '#' + name;
                            //</debug>
                        }

                        prototype[name] = member;
                    }
                }

                return this;
            },

            /**
             * @private
             * @static
             * @inheritable
             * @param name
             * @param member
             */
            addMember: function(name, member) {
                if (typeof member == 'function' && !member.$isClass && member !== Ext.emptyFn && member !== Ext.identityFn) {
                    member.$owner = this;
                    member.$name = name;
                    //<debug>
                    member.displayName = (this.$className || '') + '#' + name;
                    //</debug>
                }

                this.prototype[name] = member;
                return this;
            },

            /**
             * Adds members to class.
             * @static
             * @inheritable
             * @deprecated 4.1 Use {@link #addMembers} instead.
             */
            implement: function() {
                this.addMembers.apply(this, arguments);
            },

            /**
             * Borrow another class' members to the prototype of this class.
             *
             *     Ext.define('Bank', {
             *         money: '$$$',
             *         printMoney: function() {
             *             alert('$$$$$$$');
             *         }
             *     });
             *
             *     Ext.define('Thief', {
             *         ...
             *     });
             *
             *     Thief.borrow(Bank, ['money', 'printMoney']);
             *
             *     var steve = new Thief();
             *
             *     alert(steve.money); // alerts '$$$'
             *     steve.printMoney(); // alerts '$$$$$$$'
             *
             * @param {Ext.Base} fromClass The class to borrow members from
             * @param {Array/String} members The names of the members to borrow
             * @return {Ext.Base} this
             * @static
             * @inheritable
             * @private
             */
            borrow: function(fromClass, members) {
                //<debug>
                Ext.classSystemMonitor && Ext.classSystemMonitor(this, 'Ext.Base#borrow', arguments);
                //</debug>

                var prototype = this.prototype,
                    fromPrototype = fromClass.prototype,
                    //<debug>
                    className = Ext.getClassName(this),
                    //</debug>
                    i, ln, name, fn, toBorrow;

                members = Ext.Array.from(members);

                for (i = 0,ln = members.length; i < ln; i++) {
                    name = members[i];

                    toBorrow = fromPrototype[name];

                    if (typeof toBorrow == 'function') {
                        fn = Ext.Function.clone(toBorrow);

                        //<debug>
                        if (className) {
                            fn.displayName = className + '#' + name;
                        }
                        //</debug>

                        fn.$owner = this;
                        fn.$name = name;

                        prototype[name] = fn;
                    }
                    else {
                        prototype[name] = toBorrow;
                    }
                }

                return this;
            },

            /**
             * Override members of this class. Overridden methods can be invoked via
             * {@link Ext.Base#callParent}.
             *
             *     Ext.define('My.Cat', {
             *         constructor: function() {
             *             alert("I'm a cat!");
             *         }
             *     });
             *
             *     My.Cat.override({
             *         constructor: function() {
             *             alert("I'm going to be a cat!");
             *
             *             this.callParent(arguments);
             *
             *             alert("Meeeeoooowwww");
             *         }
             *     });
             *
             *     var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
             *                               // alerts "I'm a cat!"
             *                               // alerts "Meeeeoooowwww"
             *
             * As of 4.1, direct use of this method is deprecated. Use {@link Ext#define Ext.define}
             * instead:
             *
             *     Ext.define('My.CatOverride', {
             *         override: 'My.Cat',
             *         constructor: function() {
             *             alert("I'm going to be a cat!");
             *
             *             this.callParent(arguments);
             *
             *             alert("Meeeeoooowwww");
             *         }
             *     });
             *
             * The above accomplishes the same result but can be managed by the {@link Ext.Loader}
             * which can properly order the override and its target class and the build process
             * can determine whether the override is needed based on the required state of the
             * target class (My.Cat).
             *
             * @param {Object} members The properties to add to this class. This should be
             * specified as an object literal containing one or more properties.
             * @return {Ext.Base} this class
             * @static
             * @inheritable
             * @markdown
             * @deprecated 4.1.0 Use {@link Ext#define Ext.define} instead
             */
            override: function(members) {
                var me = this,
                    enumerables = Ext.enumerables,
                    target = me.prototype,
                    cloneFunction = Ext.Function.clone,
                    name, index, member, statics, names, previous;

                if (arguments.length === 2) {
                    name = members;
                    members = {};
                    members[name] = arguments[1];
                    enumerables = null;
                }

                do {
                    names = []; // clean slate for prototype (1st pass) and static (2nd pass)
                    statics = null; // not needed 1st pass, but needs to be cleared for 2nd pass

                    for (name in members) { // hasOwnProperty is checked in the next loop...
                        if (name == 'statics') {
                            statics = members[name];
                        } else if (name == 'inheritableStatics'){
                            me.addInheritableStatics(members[name]);
                        } else if (name == 'config') {
                            me.addConfig(members[name], true);
                        } else {
                            names.push(name);
                        }
                    }

                    if (enumerables) {
                        names.push.apply(names, enumerables);
                    }

                    for (index = names.length; index--; ) {
                        name = names[index];

                        if (members.hasOwnProperty(name)) {
                            member = members[name];

                            if (typeof member == 'function' && !member.$className && member !== Ext.emptyFn && member !== Ext.identityFn) {
                                if (typeof member.$owner != 'undefined') {
                                    member = cloneFunction(member);
                                }

                                //<debug>
                                if (me.$className) {
                                    member.displayName = me.$className + '#' + name;
                                }
                                //</debug>

                                member.$owner = me;
                                member.$name = name;

                                previous = target[name];
                                if (previous) {
                                    member.$previous = previous;
                                }
                            }

                            target[name] = member;
                        }
                    }

                    target = me; // 2nd pass is for statics
                    members = statics; // statics will be null on 2nd pass
                } while (members);

                return this;
            },

            // Documented downwards
            callParent: function(args) {
                var method;

                // This code is intentionally inlined for the least number of debugger stepping
                return (method = this.callParent.caller) && (method.$previous ||
                      ((method = method.$owner ? method : method.caller) &&
                            method.$owner.superclass.self[method.$name])).apply(this, args || noArgs);
            },

            // Documented downwards
            callSuper: function(args) {
                var method;

                // This code is intentionally inlined for the least number of debugger stepping
                return (method = this.callSuper.caller) &&
                        ((method = method.$owner ? method : method.caller) &&
                          method.$owner.superclass.self[method.$name]).apply(this, args || noArgs);
            },

            //<feature classSystem.mixins>
            /**
             * Used internally by the mixins pre-processor
             * @private
             * @static
             * @inheritable
             */
            mixin: function(name, mixinClass) {
                var me = this,
                    mixin = mixinClass.prototype,
                    prototype = me.prototype,
                    key, statics, i, ln, staticName,
                    mixinValue, hookKey, hookFunction;

                if (typeof mixin.onClassMixedIn != 'undefined') {
                    mixin.onClassMixedIn.call(mixinClass, me);
                }

                if (!prototype.hasOwnProperty('mixins')) {
                    if ('mixins' in prototype) {
                        prototype.mixins = Ext.Object.chain(prototype.mixins);
                    }
                    else {
                        prototype.mixins = {};
                    }
                }

                for (key in mixin) {
                    mixinValue = mixin[key];
                    if (key === 'mixins') {
                        Ext.merge(prototype.mixins, mixinValue);
                    }
                    else if (key === 'xhooks') {
                        for (hookKey in mixinValue) {
                            hookFunction = mixinValue[hookKey];

                            // Mixed in xhook methods cannot call a parent.
                            hookFunction.$previous = Ext.emptyFn;

                            if (prototype.hasOwnProperty(hookKey)) {

                                // Pass the hook function, and the existing function which it is to underride.
                                // The existing function has its $previous pointer replaced by a closure
                                // which calls the hookFunction and then the existing function's original $previous
                                hookFunctionFactory(hookFunction, prototype[hookKey], hookKey, me);
                            } else {
                                // There's no original function, so generate an implementation which calls
                                // the hook function. It will not get any $previous pointer.
                                prototype[hookKey] = hookFunctionFactory(hookFunction, null, hookKey, me);
                            }
                        }
                    }
                    else if (!(key === 'mixinId' || key === 'config') && (prototype[key] === undefined)) {
                        prototype[key] = mixinValue;
                    }
                }

                //<feature classSystem.inheritableStatics>
                // Mixin statics inheritance
                statics = mixin.$inheritableStatics;

                if (statics) {
                    for (i = 0, ln = statics.length; i < ln; i++) {
                        staticName = statics[i];

                        if (!me.hasOwnProperty(staticName)) {
                            me[staticName] = mixinClass[staticName];
                        }
                    }
                }
                //</feature>

                //<feature classSystem.config>
                if ('config' in mixin) {
                    me.addConfig(mixin.config, false);
                }
                //</feature>

                prototype.mixins[name] = mixin;
                return me;
            },
            //</feature>

            /**
             * Get the current class' name in string format.
             *
             *     Ext.define('My.cool.Class', {
             *         constructor: function() {
             *             alert(this.self.getName()); // alerts 'My.cool.Class'
             *         }
             *     });
             *
             *     My.cool.Class.getName(); // 'My.cool.Class'
             *
             * @return {String} className
             * @static
             * @inheritable
             */
            getName: function() {
                return Ext.getClassName(this);
            },

            /**
             * Create aliases for existing prototype methods. Example:
             *
             *     Ext.define('My.cool.Class', {
             *         method1: function() { ... },
             *         method2: function() { ... }
             *     });
             *
             *     var test = new My.cool.Class();
             *
             *     My.cool.Class.createAlias({
             *         method3: 'method1',
             *         method4: 'method2'
             *     });
             *
             *     test.method3(); // test.method1()
             *
             *     My.cool.Class.createAlias('method5', 'method3');
             *
             *     test.method5(); // test.method3() -> test.method1()
             *
             * @param {String/Object} alias The new method name, or an object to set multiple aliases. See
             * {@link Ext.Function#flexSetter flexSetter}
             * @param {String/Object} origin The original method name
             * @static
             * @inheritable
             * @method
             */
            createAlias: flexSetter(function(alias, origin) {
                this.override(alias, function() {
                    return this[origin].apply(this, arguments);
                });
            }),

            /**
             * @private
             * @static
             * @inheritable
             */
            addXtype: function(xtype) {
                var prototype = this.prototype,
                    xtypesMap = prototype.xtypesMap,
                    xtypes = prototype.xtypes,
                    xtypesChain = prototype.xtypesChain;

                if (!prototype.hasOwnProperty('xtypesMap')) {
                    xtypesMap = prototype.xtypesMap = Ext.merge({}, prototype.xtypesMap || {});
                    xtypes = prototype.xtypes = prototype.xtypes ? [].concat(prototype.xtypes) : [];
                    xtypesChain = prototype.xtypesChain = prototype.xtypesChain ? [].concat(prototype.xtypesChain) : [];
                    prototype.xtype = xtype;
                }

                if (!xtypesMap[xtype]) {
                    xtypesMap[xtype] = true;
                    xtypes.push(xtype);
                    xtypesChain.push(xtype);
                    Ext.ClassManager.setAlias(this, 'widget.' + xtype);
                }

                return this;
            }
        });

        Base.implement({
            /** @private */
            isInstance: true,

            /** @private */
            $className: 'Ext.Base',

            /** @private */
            configClass: Ext.emptyFn,

            /** @private */
            initConfigList: [],

            /** @private */
            configMap: {},

            /** @private */
            initConfigMap: {},

            /**
             * Get the reference to the class from which this object was instantiated. Note that unlike {@link Ext.Base#self},
             * `this.statics()` is scope-independent and it always returns the class from which it was called, regardless of what
             * `this` points to during run-time
             *
             *     Ext.define('My.Cat', {
             *         statics: {
             *             totalCreated: 0,
             *             speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
             *         },
             *
             *         constructor: function() {
             *             var statics = this.statics();
             *
             *             alert(statics.speciesName);     // always equals to 'Cat' no matter what 'this' refers to
             *                                             // equivalent to: My.Cat.speciesName
             *
             *             alert(this.self.speciesName);   // dependent on 'this'
             *
             *             statics.totalCreated++;
             *         },
             *
             *         clone: function() {
             *             var cloned = new this.self;                      // dependent on 'this'
             *
             *             cloned.groupName = this.statics().speciesName;   // equivalent to: My.Cat.speciesName
             *
             *             return cloned;
             *         }
             *     });
             *
             *
             *     Ext.define('My.SnowLeopard', {
             *         extend: 'My.Cat',
             *
             *         statics: {
             *             speciesName: 'Snow Leopard'     // My.SnowLeopard.speciesName = 'Snow Leopard'
             *         },
             *
             *         constructor: function() {
             *             this.callParent();
             *         }
             *     });
             *
             *     var cat = new My.Cat();                 // alerts 'Cat', then alerts 'Cat'
             *
             *     var snowLeopard = new My.SnowLeopard(); // alerts 'Cat', then alerts 'Snow Leopard'
             *
             *     var clone = snowLeopard.clone();
             *     alert(Ext.getClassName(clone));         // alerts 'My.SnowLeopard'
             *     alert(clone.groupName);                 // alerts 'Cat'
             *
             *     alert(My.Cat.totalCreated);             // alerts 3
             *
             * @protected
             * @return {Ext.Class}
             */
            statics: function() {
                var method = this.statics.caller,
                    self = this.self;

                if (!method) {
                    return self;
                }

                return method.$owner;
            },

            /**
             * Call the "parent" method of the current method. That is the method previously
             * overridden by derivation or by an override (see {@link Ext#define}).
             *
             *      Ext.define('My.Base', {
             *          constructor: function (x) {
             *              this.x = x;
             *          },
             *
             *          statics: {
             *              method: function (x) {
             *                  return x;
             *              }
             *          }
             *      });
             *
             *      Ext.define('My.Derived', {
             *          extend: 'My.Base',
             *
             *          constructor: function () {
             *              this.callParent([21]);
             *          }
             *      });
             *
             *      var obj = new My.Derived();
             *
             *      alert(obj.x);  // alerts 21
             *
             * This can be used with an override as follows:
             *
             *      Ext.define('My.DerivedOverride', {
             *          override: 'My.Derived',
             *
             *          constructor: function (x) {
             *              this.callParent([x*2]); // calls original My.Derived constructor
             *          }
             *      });
             *
             *      var obj = new My.Derived();
             *
             *      alert(obj.x);  // now alerts 42
             *
             * This also works with static methods.
             *
             *      Ext.define('My.Derived2', {
             *          extend: 'My.Base',
             *
             *          statics: {
             *              method: function (x) {
             *                  return this.callParent([x*2]); // calls My.Base.method
             *              }
             *          }
             *      });
             *
             *      alert(My.Base.method(10);     // alerts 10
             *      alert(My.Derived2.method(10); // alerts 20
             *
             * Lastly, it also works with overridden static methods.
             *
             *      Ext.define('My.Derived2Override', {
             *          override: 'My.Derived2',
             *
             *          statics: {
             *              method: function (x) {
             *                  return this.callParent([x*2]); // calls My.Derived2.method
             *              }
             *          }
             *      });
             *
             *      alert(My.Derived2.method(10); // now alerts 40
             *
             * To override a method and replace it and also call the superclass method, use
             * {@link #callSuper}. This is often done to patch a method to fix a bug.
             *
             * @protected
             * @param {Array/Arguments} args The arguments, either an array or the `arguments` object
             * from the current method, for example: `this.callParent(arguments)`
             * @return {Object} Returns the result of calling the parent method
             */
            callParent: function(args) {
                // NOTE: this code is deliberately as few expressions (and no function calls)
                // as possible so that a debugger can skip over this noise with the minimum number
                // of steps. Basically, just hit Step Into until you are where you really wanted
                // to be.
                var method,
                    superMethod = (method = this.callParent.caller) && (method.$previous ||
                            ((method = method.$owner ? method : method.caller) &&
                                    method.$owner.superclass[method.$name]));

                //<debug error>
                if (!superMethod) {
                    method = this.callParent.caller;
                    var parentClass, methodName;

                    if (!method.$owner) {
                        if (!method.caller) {
                            throw new Error("Attempting to call a protected method from the public scope, which is not allowed");
                        }

                        method = method.caller;
                    }

                    parentClass = method.$owner.superclass;
                    methodName = method.$name;

                    if (!(methodName in parentClass)) {
                        throw new Error("this.callParent() was called but there's no such method (" + methodName +
                                    ") found in the parent class (" + (Ext.getClassName(parentClass) || 'Object') + ")");
                    }
                }
                //</debug>

                return superMethod.apply(this, args || noArgs);
            },

            /**
             * This method is used by an override to call the superclass method but bypass any
             * overridden method. This is often done to "patch" a method that contains a bug
             * but for whatever reason cannot be fixed directly.
             *
             * Consider:
             *
             *      Ext.define('Ext.some.Class', {
             *          method: function () {
             *              console.log('Good');
             *          }
             *      });
             *
             *      Ext.define('Ext.some.DerivedClass', {
             *          method: function () {
             *              console.log('Bad');
             *
             *              // ... logic but with a bug ...
             *
             *              this.callParent();
             *          }
             *      });
             *
             * To patch the bug in `DerivedClass.method`, the typical solution is to create an
             * override:
             *
             *      Ext.define('App.paches.DerivedClass', {
             *          override: 'Ext.some.DerivedClass',
             *
             *          method: function () {
             *              console.log('Fixed');
             *
             *              // ... logic but with bug fixed ...
             *
             *              this.callSuper();
             *          }
             *      });
             *
             * The patch method cannot use `callParent` to call the superclass `method` since
             * that would call the overridden method containing the bug. In other words, the
             * above patch would only produce "Fixed" then "Good" in the console log, whereas,
             * using `callParent` would produce "Fixed" then "Bad" then "Good".
             *
             * @protected
             * @param {Array/Arguments} args The arguments, either an array or the `arguments` object
             * from the current method, for example: `this.callSuper(arguments)`
             * @return {Object} Returns the result of calling the superclass method
             */
            callSuper: function(args) {
                // NOTE: this code is deliberately as few expressions (and no function calls)
                // as possible so that a debugger can skip over this noise with the minimum number
                // of steps. Basically, just hit Step Into until you are where you really wanted
                // to be.
                var method,
                    superMethod = (method = this.callSuper.caller) &&
                            ((method = method.$owner ? method : method.caller) &&
                              method.$owner.superclass[method.$name]);

                //<debug error>
                if (!superMethod) {
                    method = this.callSuper.caller;
                    var parentClass, methodName;

                    if (!method.$owner) {
                        if (!method.caller) {
                            throw new Error("Attempting to call a protected method from the public scope, which is not allowed");
                        }

                        method = method.caller;
                    }

                    parentClass = method.$owner.superclass;
                    methodName = method.$name;

                    if (!(methodName in parentClass)) {
                        throw new Error("this.callSuper() was called but there's no such method (" + methodName +
                                    ") found in the parent class (" + (Ext.getClassName(parentClass) || 'Object') + ")");
                    }
                }
                //</debug>

                return superMethod.apply(this, args || noArgs);
            },

            /**
             * @property {Ext.Class} self
             *
             * Get the reference to the current class from which this object was instantiated. Unlike {@link Ext.Base#statics},
             * `this.self` is scope-dependent and it's meant to be used for dynamic inheritance. See {@link Ext.Base#statics}
             * for a detailed comparison
             *
             *     Ext.define('My.Cat', {
             *         statics: {
             *             speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
             *         },
             *
             *         constructor: function() {
             *             alert(this.self.speciesName); // dependent on 'this'
             *         },
             *
             *         clone: function() {
             *             return new this.self();
             *         }
             *     });
             *
             *
             *     Ext.define('My.SnowLeopard', {
             *         extend: 'My.Cat',
             *         statics: {
             *             speciesName: 'Snow Leopard'         // My.SnowLeopard.speciesName = 'Snow Leopard'
             *         }
             *     });
             *
             *     var cat = new My.Cat();                     // alerts 'Cat'
             *     var snowLeopard = new My.SnowLeopard();     // alerts 'Snow Leopard'
             *
             *     var clone = snowLeopard.clone();
             *     alert(Ext.getClassName(clone));             // alerts 'My.SnowLeopard'
             *
             * @protected
             */
            self: Base,

            // Default constructor, simply returns `this`
            constructor: function() {
                return this;
            },

            //<feature classSystem.config>
            /**
             * Initialize configuration for this class. a typical example:
             *
             *     Ext.define('My.awesome.Class', {
             *         // The default config
             *         config: {
             *             name: 'Awesome',
             *             isAwesome: true
             *         },
             *
             *         constructor: function(config) {
             *             this.initConfig(config);
             *         }
             *     });
             *
             *     var awesome = new My.awesome.Class({
             *         name: 'Super Awesome'
             *     });
             *
             *     alert(awesome.getName()); // 'Super Awesome'
             *
             * @protected
             * @param {Object} config
             * @return {Ext.Base} this
             */
            initConfig: function(config) {
                var instanceConfig = config,
                    configNameCache = Ext.Class.configNameCache,
                    defaultConfig = new this.configClass(),
                    defaultConfigList = this.initConfigList,
                    hasConfig = this.configMap,
                    nameMap, i, ln, name, initializedName;

                this.initConfig = Ext.emptyFn;

                this.initialConfig = instanceConfig || {};

                this.config = config = (instanceConfig) ? Ext.merge(defaultConfig, config) : defaultConfig;

                if (instanceConfig) {
                    defaultConfigList = defaultConfigList.slice();

                    for (name in instanceConfig) {
                        if (hasConfig[name]) {
                            if (instanceConfig[name] !== null) {
                                defaultConfigList.push(name);
                                this[configNameCache[name].initialized] = false;
                            }
                        }
                    }
                }

                for (i = 0,ln = defaultConfigList.length; i < ln; i++) {
                    name = defaultConfigList[i];
                    nameMap = configNameCache[name];
                    initializedName = nameMap.initialized;

                    if (!this[initializedName]) {
                        this[initializedName] = true;
                        this[nameMap.set].call(this, config[name]);
                    }
                }

                return this;
            },

            /**
             * @private
             * @param config
             */
            hasConfig: function(name) {
                return Boolean(this.configMap[name]);
            },

            /**
             * @private
             */
            setConfig: function(config, applyIfNotSet) {
                if (!config) {
                    return this;
                }

                var configNameCache = Ext.Class.configNameCache,
                    currentConfig = this.config,
                    hasConfig = this.configMap,
                    initialConfig = this.initialConfig,
                    name, value;

                applyIfNotSet = Boolean(applyIfNotSet);

                for (name in config) {
                    if (applyIfNotSet && initialConfig.hasOwnProperty(name)) {
                        continue;
                    }

                    value = config[name];
                    currentConfig[name] = value;

                    if (hasConfig[name]) {
                        this[configNameCache[name].set](value);
                    }
                }

                return this;
            },

            /**
             * @private
             * @param name
             */
            getConfig: function(name) {
                var configNameCache = Ext.Class.configNameCache;

                return this[configNameCache[name].get]();
            },

            /**
             * Returns the initial configuration passed to constructor when instantiating
             * this class.
             * @param {String} [name] Name of the config option to return.
             * @return {Object/Mixed} The full config object or a single config value
             * when `name` parameter specified.
             */
            getInitialConfig: function(name) {
                var config = this.config;

                if (!name) {
                    return config;
                }
                else {
                    return config[name];
                }
            },

            /**
             * @private
             * @param names
             * @param callback
             * @param scope
             */
            onConfigUpdate: function(names, callback, scope) {
                var self = this.self,
                    //<debug>
                    className = self.$className,
                    //</debug>
                    i, ln, name,
                    updaterName, updater, newUpdater;

                names = Ext.Array.from(names);

                scope = scope || this;

                for (i = 0,ln = names.length; i < ln; i++) {
                    name = names[i];
                    updaterName = 'update' + Ext.String.capitalize(name);
                    updater = this[updaterName] || Ext.emptyFn;
                    newUpdater = function() {
                        updater.apply(this, arguments);
                        scope[callback].apply(scope, arguments);
                    };
                    newUpdater.$name = updaterName;
                    newUpdater.$owner = self;
                    //<debug>
                    newUpdater.displayName = className + '#' + updaterName;
                    //</debug>

                    this[updaterName] = newUpdater;
                }
            },
            //</feature>

            /**
             * @private
             */
            destroy: function() {
                this.destroy = Ext.emptyFn;
            }
        });

        /**
         * Call the original method that was previously overridden with {@link Ext.Base#override}
         *
         *     Ext.define('My.Cat', {
         *         constructor: function() {
         *             alert("I'm a cat!");
         *         }
         *     });
         *
         *     My.Cat.override({
         *         constructor: function() {
         *             alert("I'm going to be a cat!");
         *
         *             this.callOverridden();
         *
         *             alert("Meeeeoooowwww");
         *         }
         *     });
         *
         *     var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
         *                               // alerts "I'm a cat!"
         *                               // alerts "Meeeeoooowwww"
         *
         * @param {Array/Arguments} args The arguments, either an array or the `arguments` object
         * from the current method, for example: `this.callOverridden(arguments)`
         * @return {Object} Returns the result of calling the overridden method
         * @protected
         * @deprecated as of 4.1. Use {@link #callParent} instead.
         */
        Base.prototype.callOverridden = Base.prototype.callParent;

        Ext.Base = Base;

    }(Ext.Function.flexSetter));