SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 3)
    Identifier t1.x
    Identifier t2.x
    Identifier y
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 2)
           Identifier x
           Identifier y
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function VALUES (children 1)
              ExpressionList (children 2)
               Literal \'x UInt16, y UInt16\'
               Literal Tuple_(UInt64_0, UInt64_1)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 2)
           Identifier x
           Identifier z
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function VALUES (children 1)
              ExpressionList (children 2)
               Literal \'x UInt16, z UInt16\'
               Literal Tuple_(UInt64_2, UInt64_3)
     TableJoin
