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)
        Identifier number
        Literal UInt64_2
      Literal Tuple_(UInt64_1, NULL, UInt64_3)
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.numbers
   Literal UInt64_5