public function testCallback()
{
$this->assertEquals('substr', fCore::callback('substr'));
$this->assertEquals('testing', fCore::callback('testing'));
$this->assertEquals(array('Class', 'method'), fCore::callback(array('Class', 'method')));
$this->assertEquals(array('Class', 'method'), fCore::callback('Class::method'));
$this->assertEquals(array('OtherClass', 'method2'), fCore::callback('OtherClass::method2'));
}