SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function dictGetHierarchy (children 1)
     ExpressionList (children 2)
      Literal \'01681_database_for_flat_dictionary.flat_dictionary_simple_key_hierarchy\'
      Function toUInt64 (children 1)
       ExpressionList (children 1)
        Literal UInt64_1