SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function toUInt8 (children 1)
     ExpressionList (children 1)
      Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function values (children 1)
       ExpressionList (children 6)
        Literal \'x Nullable(String)\'
        Literal \'42\'
        Literal NULL
        Literal \'0\'
        Literal \'\'
        Literal \'256\'