@Nullable
  private PsiComment getCommentAtOffset(int offset) {
    PsiElement elt = myFile.getViewProvider().findElementAt(offset);
    if (elt == null) return null;
    return PsiTreeUtil.getParentOfType(elt, PsiComment.class, false);
  }
@Nullable
  private PsiComment getCommentAtOffset(int offset)