    # File lib/fog/aws/requests/auto_scaling/set_desired_capacity.rb, line 69
            def set_desired_capacity(auto_scaling_group_name, desired_capacity, options = {})
              unless data[:auto_scaling_groups].has_key?(auto_scaling_group_name)
                Fog::AWS::AutoScaling::ValidationError.new('AutoScalingGroup name not found - null')
              end
              data[:auto_scaling_groups][auto_scaling_group_name]['DesiredCapacity'] = desired_capacity

              response = Excon::Response.new
              response.status = 200
              response.body = {
                'ResponseMetadata' => { 'RequestId' => Fog::AWS::Mock.request_id }
              }
              response
            end