@Override
    protected void appendChildrenTo(@NotNull final Collection<? super ConvenientNode> children) {
      for (VirtualFile child : getObject().getChildren()) {
        if (myFilter.accept(child)) {
          children.add(new FileNode(child, myProject, myFilter));
        }
      }
    }
@Override
    protected void appendChildrenTo(@NotNull final Collection<? super ConvenientNode> children)