code: public static boolean isPropertyAllowed(Class defClass, String propertyName)
      {
          HashMap props = (HashMap)_properties.get(defClass);
  
          return (props == null ? true : props.containsKey(propertyName));
      }
docs: Checks whether the property of the given name is allowed for the model element.
  
  @param defClass     The class of the model element
  @param propertyName The name of the property
  @return <code>true</code> if the property is allowed for this type of model elements