code: public String getIdName() {
          String result = null;
          if (idAccessor != null) {
              result = idAccessor.getPropertyName();
          }
          return result;
      }
docs: Returns the name of the idfield of the given entity. If no id field exists, null is returned.
  
  @return the name of the idproperty, or null if no geometryproperty exists