title: What is this hex value for in the Chrome debugger?
body: <p>I am just curious as to why there appears to be a hex number associated with each source in this Chrome debugger output here ...</p>
  
  <pre><code>WebSocket is already in CLOSING or CLOSED state.
  (anonymous) @ websocket.js?13d9:192
  exports.encodePacket @ browser.js?9636:123
  (anonymous) @ websocket.js?13d9:170
  WS.write @ websocket.js?13d9:202
  Transport.send @ transport.js?87a5:110
  Socket.flush @ socket.js?1006:565
  Socket.sendPacket @ socket.js?1006:625
  Socket.ping @ socket.js?1006:529
  (anonymous) @ socket.js?1006:516
  setTimeout (async)
  Socket.setPing @ socket.js?1006:514
  Socket.onPacket @ socket.js?1006:445
  (anonymous) @ socket.js?1006:273
  Emitter.emit @ index.js?ea2f:133
  Transport.onPacket @ transport.js?87a5:145
  Transport.onData @ transport.js?87a5:137
  ws.onmessage @ websocket.js?13d9:147
  </code></pre>
  
  <p>For example, the source <code>websocket.js</code> correlates to <code>13d9</code>.</p>
  
  <p>Where does this hex value come from and what is it used for?</p>
  
  <p>I am not concerned with the actual error in this case, I'm just using it for an example.</p>