remove method
Removes callback
from the list of listeners.
Implementation
void remove(EventSignalCallback<T> callback) {
final idx = _listeners.indexOf(callback);
if (idx > -1) {
if (idx <= _iterDispatchers) {
_iterDispatchers--;
}
--_iterLen;
_listeners.removeAt(idx);
} else {
_listenersOnce.remove(callback);
}
}