@Nullable
  public CompositePackagingElement<?> getLastParent() {
    PackagingElementPath path = this;
    while (path != EMPTY) {
      if (path.myLastElement instanceof CompositePackagingElement<?>) {
        return (CompositePackagingElement)path.myLastElement;
      }
      path = path.myParentPath;
    }
    return null;
  }
@Nullable
  public CompositePackagingElement<?> getLastParent()