off method

void off(dynamic eventName, [ EventCallback? f ])

Implementation

void off(eventName, [EventCallback? f]) {
  var list = _emap[eventName];
  if (eventName == null || list == null) return;
  list.remove(f);
  // if (f == null) {
  //   _emap[eventName] = null;
  // } else {
  // list.remove(f);
  // }
}