It's a fairly common UI pattern in chat programs. You have a set of people talking in a chatroom, and one person sends multiple messages in a row. Instead of styling each of these messages like one-off messages, you style the additional messages so they appear as a unit with the first message by that author, until interrupted by someone else. You remove horizontal border lines, or you make the message author's name only appear once, or you do some nice thing with padding. Whatever.
This is a pretty common pattern. It's also something that obviously ought to be handled by the presentation layer--your application code shouldn't care what order the chat messages happen to come in, and you shouldn't have to add wrapper divs and other jiggery-pokery when subsequent messages come in or get deleted and worry about determining whether this "chunk" of messages is interrupted by other chats or not.
Unless the number