code: public void revisitThrowEvents(Definitions def) {
          List<RootElement> rootElements = def.getRootElements();
          List<Signal> toAddSignals = new ArrayList<Signal>();
          Set<Error> toAddErrors = new HashSet<Error>();
          Set<Escalation> toAddEscalations = new HashSet<Escalation>();
          Set<Message> toAddMessages = new HashSet<Message>();
          Set<ItemDefinition> toAddItemDefinitions = new HashSet<ItemDefinition>();
          for (RootElement root : rootElements) {
              if (root instanceof Process) {
                  setThrowEventsInfo((Process) root,
                                     def,
                                     rootElements,
                                     toAddSignals,
                                     toAddErrors,
                                     toAddEscalations,
                                     toAddMessages,
                                     toAddItemDefinitions);
              }
          }
          for (Lane lane : _lanes) {
              setThrowEventsInfoForLanes(lane,
                                         def,
                                         rootElements,
                                         toAddSignals,
                                         toAddErrors,
                                         toAddEscalations,
                                         toAddMessages,
                                         toAddItemDefinitions);
          }
          for (Signal s : toAddSignals) {
              def.getRootElements().add(s);
          }
          for (Error er : toAddErrors) {
              def.getRootElements().add(er);
          }
          for (Escalation es : toAddEscalations) {
              def.getRootElements().add(es);
          }
          for (ItemDefinition idef : toAddItemDefinitions) {
              def.getRootElements().add(idef);
          }
          for (Message msg : toAddMessages) {
              def.getRootElements().add(msg);
          }
      }
docs: Updates event definitions for all throwing events.
  @param def Definitions