    # 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