SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function dictGetKeys (children 1)
     ExpressionList (children 3)
      Literal \'dict_valexpr\'
      Literal \'u64\'
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal Int64_-42
        Literal \'Nullable(Int32)\'
