code: public void marshall(RDSMetadata rDSMetadata, ProtocolMarshaller protocolMarshaller) {
  
          if (rDSMetadata == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(rDSMetadata.getDatabase(), DATABASE_BINDING);
              protocolMarshaller.marshall(rDSMetadata.getDatabaseUserName(), DATABASEUSERNAME_BINDING);
              protocolMarshaller.marshall(rDSMetadata.getSelectSqlQuery(), SELECTSQLQUERY_BINDING);
              protocolMarshaller.marshall(rDSMetadata.getResourceRole(), RESOURCEROLE_BINDING);
              protocolMarshaller.marshall(rDSMetadata.getServiceRole(), SERVICEROLE_BINDING);
              protocolMarshaller.marshall(rDSMetadata.getDataPipelineId(), DATAPIPELINEID_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }
docs: Marshall the given parameter object.