# File lib/fog/aws/requests/ecs/deregister_container_instance.rb, line 26
        def deregister_container_instance(params={})
          response = Excon::Response.new
          response.status = 200

          instance_id = params.delete('containerInstance')
          instance_error = "ClientException => Container instance can not be blank."
          raise Fog::AWS::ECS::Error, instance_error unless instance_id

          if match = instance_id.match(/^arn:aws:ecs:.+:\d{1,12}:container-instance\/(.+)$/)
            i = self.data[:container_instances].index do |inst|
              inst['containerInstanceArn'].eql?(instance_id)
            end
          else
            i = self.data[:container_instances].index do |inst|
              inst['containerInstanceArn'].match(/#{instance_id}$/)
            end
          end

          msg = "ClientException => Referenced container instance #{instance_id} not found."
          raise Fog::AWS::ECS::Error, msg unless i

          instance = self.data[:container_instances][i]
          self.data[:container_instances].delete_at(i)

          response.body = {
            'DeregisterContainerInstanceResult' => {
              'containerInstance' => instance
            },
            'ResponseMetadata' => {
              'RequestId' => Fog::AWS::Mock.request_id
            }
          }
          response
        end