code: public static boolean sendOnEvent(Object filter, FilterDescriptor descriptor, String id,
          FilterEventParameters parameters) throws FilterException
      {
          FilterElementDescriptor elementDescriptor = descriptor.getElement(id);
  
          if (elementDescriptor != null && elementDescriptor.getOnMethod() != null) {
              sendEvent(elementDescriptor.getOnMethod(), elementDescriptor, filter, parameters);
          } else if (filter instanceof UnknownFilter) {
              ((UnknownFilter) filter).onUnknwon(id, parameters);
          } else {
              return false;
          }
  
          return true;
      }
docs: Call passed on event if possible.
  
  @param filter the filter
  @param descriptor the descriptor of the filter
  @param id the id of the event
  @param parameters the parameters of the event
  @return true if the event has been sent, false otherwise
  @throws FilterException when the passed filter exposes the event but failed anyway