SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function dictGetKeys (children 1)
     ExpressionList (children 3)
      Literal \'dict_valexpr\'
      Literal \'i32n\'
      Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function arrayJoin (alias x) (children 1)
            ExpressionList (children 1)
             Function array (children 1)
              ExpressionList (children 4)
               Function CAST (children 1)
                ExpressionList (children 2)
                 Literal NULL
                 Literal \'Nullable(Int32)\'
               Function CAST (children 1)
                ExpressionList (children 2)
                 Literal UInt64_10
                 Literal \'Nullable(Int32)\'
               Function CAST (children 1)
                ExpressionList (children 2)
                 Literal NULL
                 Literal \'Nullable(Int32)\'
               Function CAST (children 1)
                ExpressionList (children 2)
                 Literal Int64_-5
                 Literal \'Nullable(Int32)\'
