public function testFirstMethod()
 {
     $GLOBALS['__event.test.foo'] = false;
     $e = new Dispatcher();
     $e->listen('foo', function () {
         return 'baz';
     });
     $e->listen('foo', function () {
         $GLOBALS['__event.test.foo'] = true;
         return 'bar';
     });
     $response = $e->first('foo');
     $this->assertEquals('baz', $response);
     $this->assertFalse($GLOBALS['__event.test.foo']);
     unset($GLOBALS['__event.test.foo']);
 }