void addTypeReference(RefJavaElement from) {
    if (from != null) {
      synchronized (this) {
        if (myInTypeReferences == null) {
          myInTypeReferences = new HashSet<>(1);
        }
        myInTypeReferences.add(from);
      }
      ((RefJavaElementImpl)from).addOutTypeReference(this);
      getRefManager().fireNodeMarkedReferenced(this, from, false, false, false);
    }
  }
void addTypeReference(RefJavaElement from)