title: Extending DefaultChannelGroup
body: <p>I would like to create a class that works much like a DefaultChannelGroup, but with the one difference that the message being written belongs to a connection and the channel associated with it will not have the message written back to it.</p>
  
  <p>Think of the chat application where we should write to all other channels other than the one belonging to the user who wrote the message.</p>
  
  <p>Looking at the implementation of the DefaultChannelGroup it seems I could add a new method named write that expects a given channel and the message, and will iterate the non-server channels and skip a channel that is equals to the given channel.</p>