code: public Converter getConverterForOperation(String operId) {
          if (getConverters() != null) {
              for (Converter converter : getConverters()) {
                  if (check(converter, converter.getOperations(), operId)) {
                      return converter;
                  }
              }
          }
          if (getExternalConverters() != null) {
              for (ExternalConverter ecs : getExternalConverters()) {
                  final Converter c = PresentationManager.getPm().findExternalConverter(ecs.getId());
                  if (c != null && check(c, (ecs.getOperations() == null) ? c.getOperations() : ecs.getOperations(), operId)) {
                      //TODO Add override of properties.
                      return c;
                  }
              }
          }
          return null;
      }
docs: Looks for an aproppiate converter for the given operation id.
  @param operId The operation id
  @return The first converter that matches this operation.