SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function in (alias res) (children 1)
     ExpressionList (children 2)
      Function nullIf (children 1)
       ExpressionList (children 2)
        Function toString (children 1)
         ExpressionList (children 1)
          Identifier number
        Literal \'4\'
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 4)
          ExpressionList (children 1)
           Function nullIf (children 1)
            ExpressionList (children 2)
             Function toString (children 1)
              ExpressionList (children 1)
               Identifier number
             Literal \'2\'
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier system.numbers
          Literal UInt64_1
          Literal UInt64_3
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.numbers
   Literal UInt64_5
