code: public void revisitSignalRef(Definitions def) {
          List<RootElement> rootElements = def.getRootElements();
          for (RootElement root : rootElements) {
              if (root instanceof Process) {
                  setSignalRefForCatchEvents((Process) root,
                                             def);
                  setSignalRefForThrowEvents((Process) root,
                                             def);
                  setSignalRefForBoundaryEvents((Process) root,
                                                def);
              }
          }
      }
docs: Updates the signal ref on catch and throw event definitions (including boundary)
  @param def Definitions