title: How do I get a Faye client given a client ID?
body: <p>Faye allows you to monitor various events, such as <code>handshake</code> or <code>subscribe</code>.  These callback blocks are only supplied the <code>client_id</code> value rather than the client itself.  For example:</p>
  
  <pre><code>server = Faye::RackAdapter.new(mount: '/faye', timeout: 45)
  
  server.bind(:handshake) do |client_id|
    puts "Received handshake from #{client_id}"
  end
  </code></pre>
  
  <p>How can I access the client given the <code>client_id</code>?  Or how can I access more information in the handshake, such as cookies provided in the request header (if that info is even available)?</p>