In UML modeling, you can specify the services that instances
of a component offers to their clients.
A diagram must be open in the diagram editor and
it must contain at least one component and one interface.
To specify a provided interface, in the diagram editor,
click an interface and drag it over the Provided Interfaces compartment
of the component.
If the component is showing the external view, the provided
interface is displayed as a ball attached to the component shape.
If the component is showing the internal or class view, the interface
is displayed in the Provided Interfaces compartment.