# File lib/fog/aws/requests/compute/create_security_group.rb, line 37
        def create_security_group(name, description, vpc_id=nil)
          response = Excon::Response.new
          unless self.data[:security_groups][name]
            data = {
              'groupDescription'    => description,
              'groupName'           => name,
              'groupId'             => Fog::AWS::Mock.security_group_id,
              'ipPermissionsEgress' => [],
              'ipPermissions'       => [],
              'ownerId'             => self.data[:owner_id],
              'vpcId'               => vpc_id
            }
            self.data[:security_groups][name] = data
            response.body = {
              'requestId' => Fog::AWS::Mock.request_id,
              'groupId'   => data['groupId'],
              'return'    => true
            }
            response
          else
            raise Fog::Compute::AWS::Error.new("InvalidGroup.Duplicate => The security group '#{name}' already exists")
          end
        end