code: public void marshall(UpdateRelationalDatabaseRequest updateRelationalDatabaseRequest, ProtocolMarshaller protocolMarshaller) {
  
          if (updateRelationalDatabaseRequest == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getRelationalDatabaseName(), RELATIONALDATABASENAME_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getMasterUserPassword(), MASTERUSERPASSWORD_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getRotateMasterUserPassword(), ROTATEMASTERUSERPASSWORD_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getPreferredBackupWindow(), PREFERREDBACKUPWINDOW_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getPreferredMaintenanceWindow(), PREFERREDMAINTENANCEWINDOW_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getEnableBackupRetention(), ENABLEBACKUPRETENTION_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getDisableBackupRetention(), DISABLEBACKUPRETENTION_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getPubliclyAccessible(), PUBLICLYACCESSIBLE_BINDING);
              protocolMarshaller.marshall(updateRelationalDatabaseRequest.getApplyImmediately(), APPLYIMMEDIATELY_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }
docs: Marshall the given parameter object.