code: function(type, listener) {
          checkListener(listener);
  
          var events = this.$e;
          var listeners;
  
          if (events && (listeners = events[type])) {
              if (isFunction(listeners)) {
                  if (listeners === listener) {
                      delete events[type];
                  }
              } else {
                  for (var i=listeners.length-1; i>=0; i--) {
                      if (listeners[i] === listener) {
                          listeners.splice(i, 1);
                      }
                  }
              }
          }
  
          return this;
      }
docs: emits a 'removeListener' event iff the listener was removed