title: Socket.io threw err:fn.bind is not a function
body: <p>I got the same error while trying to build the multiroom chat application from the book "Node.js in action"
  why does it happen and how can I fix it ? please help ~</p>
  
  <pre><code>&lt;MY_PATH&gt;\chatapp\node_modules\socket.io-adapter\index.js:210
    if (fn) process.nextTick(fn.bind(null, null, sids));
                                ^
  
  TypeError: fn.bind is not a function
      at Adapter.clients (&lt;MY_PATH&gt;\chatapp\node_modules\socket.io-adapter\index.js:210:31)
      at Namespace.clients (&lt;MY_PATH&gt;\chatapp\node_modules\socket.io\lib\namespace.js:256:16)
      at updateUserList (&lt;MY_PATH&gt;\chatapp\socket\socket.js:49:41)
      at Socket.&lt;anonymous&gt; (&lt;MY_PATH&gt;\chatapp\socket\socket.js:22:7)
      at emitOne (events.js:115:13)
      at Socket.emit (events.js:210:7)
      at &lt;MY_PATH&gt;\chatapp\node_modules\socket.io\lib\socket.js:514:12
      at _combinedTickCallback (internal/process/next_tick.js:131:7)
      at process._tickCallback (internal/process/next_tick.js:180:9)
  </code></pre>