# File lib/fog/aws/requests/rds/describe_db_clusters.rb, line 30
        def describe_db_clusters(identifier=nil, opts={})
          response    = Excon::Response.new
          cluster_set = []

          if identifier
            if cluster = self.data[:clusters][identifier]
              cluster_set << cluster
            else
              raise Fog::AWS::RDS::NotFound.new("DBCluster #{identifier} not found")
            end
          else
            cluster_set = self.data[:clusters].values
          end

          response.status = 200
          response.body = {
            "ResponseMetadata"         => { "RequestId"  => Fog::AWS::Mock.request_id },
            "DescribeDBClustersResult" => { "DBClusters" => cluster_set }
          }
          response
        end