SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function plus (alias x) (children 1)
     ExpressionList (children 2)
      Function materialize (children 1)
       ExpressionList (children 1)
        Function toNullable (children 1)
         ExpressionList (children 1)
          Literal UInt64_0
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal UInt64_1
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x
    Function toColumnTypeName (children 1)
     ExpressionList (children 1)
      Identifier x