Remove 'callback' param from the unsubscribe function.

[nashvail]

Inside the unsubscribe function, the code is

var subs = cache[callback ? handle : handle[0]], 
  callback = callback || handle[1],
  len = subs ? subs.length : 0;

In case a callback is passed,

• subs becomes undefined because an array is being passed to the cache object.
• callback local variable holds the passed in callback
• len becomes 0.

The final check then...

if (subs[len] === callback) { // undefined[0] => always false
  subs.splice(len, 1);
}

...doesn't result in anything getting spliced from subs.

Please help me see the reason behind having callback as param if I have minsunderstood the code.