SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function in (children 1)
     ExpressionList (children 2)
      Function nullIf (children 1)
       ExpressionList (children 2)
        Function toString (children 1)
         ExpressionList (children 1)
          Identifier number
        Literal \'2\'
      Literal Tuple_(\'1\', NULL, \'3\')
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.numbers
   Literal UInt64_5