code: function(ev, callback, context) {
        var calls = this._callbacks || (this._callbacks = {});
        var list  = calls[ev] || (calls[ev] = []);
        list.push([callback, context]);
        return this;
      }
docs: Bind an event, specified by a string name, `ev`, to a `callback` function. Passing `"all"` will bind the callback to all events fired.