@Nullable
  private static PySequenceExpression findCollectionLiteralUnderElement(PsiElement curElem) {
    final PySequenceExpression seqExpr = PsiTreeUtil.getParentOfType(curElem, PySequenceExpression.class);
    if (seqExpr != null) {
      return seqExpr;
    }
    final PyParenthesizedExpression paren = (PyParenthesizedExpression)PsiTreeUtil.findFirstParent(curElem, element -> {
      final PyParenthesizedExpression parenthesizedExpr = as(element, PyParenthesizedExpression.class);
      return parenthesizedExpr != null && parenthesizedExpr.getContainedExpression() instanceof PyTupleExpression;
    });
    return paren != null ? ((PyTupleExpression)paren.getContainedExpression()) : null;
  }
@Nullable
  private static PySequenceExpression findCollectionLiteralUnderElement(PsiElement curElem)