title: Correct use of ChannelGroup
body: <p>For learning purposes i am expanding the SecureChatServer example of the <a href="http://netty.io/" rel="nofollow">Netty Framework</a> adding rooms.<br/>
  <br/>
  in short, every room will hold up to four chatGuests. So here are my questions:</p>
  
  <ol>
  <li>I am starting from the assumption that one connecting host will have its dedicated channel, ergo one host &lt;-> one channel. Is this correct in a default situation?</li>
  <li>Is it the intended purpose of the ChannelGroup interface to be used to group channels for a situation like this, i.e. several ChannelGroups holding each no more than 4 channels so to relay the message sent to a specific channelGroup just to the members of that group?</li>
  <li>Making my implementation of ChannelInboundHandlerAdapter sharable will cause my ChatServer to instantiate just one ChannelHandler object that will hold the states of all the different ChannelGroups?</li>
  </ol>
  
  <p>Please let me know if you need any specific code to answer, thanks.</p>