public function testExtension()
{
$extendable = new extendable();
$this->assertNull($extendable->___get('x'));
$extension = new extensionSample();
$extendable->extend($extension);
$reflection = new ReflectionObject($extendable);
//$method = $reflection->getMethod('method');
//$this->assertTrue(is_object($method));
$this->assertEquals(1, $extendable->___get('x'));
$this->assertEquals(2, $extendable->method());
}