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);
}
