public function testRemoveListenerTwice() { $result = false; $callback = function () use(&$result) { $result = true; }; $eManager = new EventManager(); $eManager->on('foo', $callback); $eManager->trigger('foo'); isTrue($result); $result = false; isTrue($eManager->removeListener('foo', $callback)); isFalse($eManager->removeListener('foo', $callback)); $eManager->trigger('foo'); isFalse($result); }