SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Subquery (alias subquery) (children 1)
     SelectWithUnionQuery (children 1)
      ExpressionList (children 1)
       SelectQuery (children 1)
        ExpressionList (children 1)
         Literal UInt64_1
    Literal UInt64_1 (alias subquery)
