    # File lib/fog/aws/requests/rds/create_db_subnet_group.rb, line 30
            def create_db_subnet_group(name, subnet_ids, description = name)
              response = Excon::Response.new
              if self.data[:subnet_groups] && self.data[:subnet_groups][name]
                raise Fog::AWS::RDS::IdentifierTaken.new("DBSubnetGroupAlreadyExists => The subnet group '#{name}' already exists")
              end

              subnets = subnet_ids.map { |snid| Fog::Compute[:aws].subnets.get(snid) }
              vpc_id = subnets.first.vpc_id

              data = {
                'DBSubnetGroupName' => name,
                'DBSubnetGroupDescription' => description,
                'SubnetGroupStatus' => 'Complete',
                'Subnets' => subnet_ids,
                'VpcId' => vpc_id
              }
              self.data[:subnet_groups][name] = data
              response.body = {
                "ResponseMetadata"=>{ "RequestId"=> Fog::AWS::Mock.request_id },
                'CreateDBSubnetGroupResult' => { 'DBSubnetGroup' => data }
              }
              response

            end