SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias a) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_1 (alias x)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias b) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1 (alias x)
           Literal UInt64_2 (alias y)
     TableJoin (children 1)
      Function and (children 1)
       ExpressionList (children 2)
        Function equals (children 1)
         ExpressionList (children 2)
          Identifier a.x
          Identifier b.x
        Function equals (children 1)
         ExpressionList (children 2)
          Identifier a.y
          Identifier b.y
