public function testCall()
{
$this->assertEquals('testing', fCore::call('substr', array('testing', 0)));
$this->assertEquals('testing', fCore::call('substr', 'testing', 0));
$this->assertEquals('test', fCore::call('substr', array('testing', 0, 4)));
$this->assertEquals('test', fCore::call('substr', 'testing', 0, 4));
}