SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 2)
         SelectQuery (children 3)
          ExpressionList (children 1)
           Asterisk
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier union_bug
          Function equals (children 1)
           ExpressionList (children 2)
            Identifier Event
            Literal \'A\'
         SelectQuery (children 3)
          ExpressionList (children 1)
           Asterisk
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier union_bug
          Function equals (children 1)
           ExpressionList (children 2)
            Identifier Event
            Literal \'B\'
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier Datetime
