public function testGetCallbacks()
 {
     $callback_name = 'callback';
     $args = ['argument 1', 'argument 2'];
     $expected = [['method' => $callback_name, 'arguments' => $args]];
     $this->object->setCallback($callback_name, $args);
     $result = $this->object->getCallbacks();
     $msg = 'Wrong PdoConnection::setCallback behavior!';
     $this->assertSame($expected, $result, $msg);
 }