lib/event-emitter.js
function removeListener(event, listener) {
  this._events = this._events || {};
  if(event in this._events) {
    this._events[event].splice(this._events[event].indexOf(listener), 1);
  }
  return this;
}
function removeListener(event, listener) {
  this._events = this._events || {};
  if(event in this._events) {
    this._events[event].splice(this._events[event].indexOf(listener), 1);
  }
  return this;
}
function removeListener ( event , listener ) { this . _events = this . _events || { } ; if ( event in this . _events ) { this . _events [ event ] . splice ( this . _events [ event ] . indexOf ( listener ) , 1 ) ; } return this ; }
Remove a listener for an event.

@param event The event name.
@param listener The event listener function.
Remove a listener for an event .