@Nullable
  private Ref<PyExpression> resolvePositionalStarExpression(@NotNull PyStarArgument starArgument, int argumentPosition) {
    assert myPosition >= 0;
    final PyExpression expr = PyPsiUtils.flattenParens(PsiTreeUtil.getChildOfAnyType(starArgument, PyListLiteralExpression.class, PyParenthesizedExpression.class,
                                                            PyStringLiteralExpression.class));
    if (expr == null) {
      return Ref.create(starArgument);
    }
    final int position = myPosition - argumentPosition;
    return getElementByIndex(expr, position);
  }
@Nullable
  private Ref<PyExpression> resolvePositionalStarExpression(@NotNull PyStarArgument starArgument, int argumentPosition)