code: public List<Return> executeEvents(final EventType _eventtype,
                                        final Parameter _param)
          throws EFapsException
      {
          final List<Return> ret = new ArrayList<>();
          if (hasEvents(_eventtype)) {
              if (this instanceof AbstractUserInterfaceObject) {
                  // add ui object to parameter
                  _param.put(ParameterValues.UIOBJECT, this);
              }
              // execute all triggers
              for (final EventDefinition evenDef : this.events.get(_eventtype)) {
                  ret.add(evenDef.execute(_param));
              }
          }
          return ret;
      }
docs: The method gets all events for the given event type and executes them in
  the given order. If no events are defined, nothing is done.
  
  @param _eventtype type of event to execute
  @param _param Parameter to be passed to the esjp
  @return List with Returns
  @throws EFapsException on error