With this class and method, it's possible to do nice things, like add methods on the fly to an object.MetaTrait.php<?phptrait MetaTrait{ private $methods = array(); public function addMethod($methodName, $methodCallable) { if (!is_callable($methodCallable)) { throw new InvalidArgumentException('Second param must be callable'); } $this->methods[$methodName] = Closure::bind($methodCallable, $this, get_class()); } public function __call($methodName, array $args) { if (isset($this->methods[$methodName])) { return call_user_func_array($this->methods[$methodName], $args); } throw RunTimeException('There is no method with the given name to call'); } }?>test.php<?phprequire 'MetaTrait.php'; class HackThursday { use MetaTrait; private $dayOfWeek = 'Thursday'; } $test = new HackThursday();$test->addMethod('when', function () { return $this->dayOfWeek;}); echo $test->when();?>