void removeEventListener(String type, EventListener listener,
    [bool useCapture]) {
  // TODO(leafp): This check is avoid a bug in our dispatch code when
  // listener is null.  The browser treats this call as a no-op in this
  // case, so it's fine to short-circuit it, but we should not have to.
  if (listener != null) {
    _removeEventListener(type, listener, useCapture);
  }
}
    © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
    https://api.dart.dev/stable/2.5.0/dart-html/EventTarget/removeEventListener.html