@Nullable
  private Ref<PyExpression> resolveNumericIndex(@NotNull PyExpression valueExpr, @NotNull Integer index) {
    if (PsiTreeUtil.instanceOf(valueExpr, PyListLiteralExpression.class, PyTupleExpression.class, PyStringLiteralExpression.class)) {
      Ref<PyExpression> elementRef = getElementByIndex(valueExpr, index);
      if (elementRef != null) return elementRef;
    }
    else if (valueExpr instanceof PyDictLiteralExpression) {
      return getElementFromDictLiteral((PyDictLiteralExpression)valueExpr, index);
    }
    else if (valueExpr instanceof PyReferenceExpression) {
      return Ref.create(valueExpr);
    }
    return null;
  }
@Nullable
  private Ref<PyExpression> resolveNumericIndex(@NotNull PyExpression valueExpr, @NotNull Integer index)