public function unregister(Listener $register) {
			$id = $register->id;
			$success = false;
			if (isset($this->_byId[$id])) {
				unset($this->_byId[$id]);
				$success = true;
			}
			foreach ($this->_bySignal as $signal => $reg) {
				if (isset($reg[$id])) {
					unset($this->_bySignal[$signal][$id]);
				}
			}
			return $success;
		}