public function testHas()
{
$builder = new ContainerBuilder();
$this->assertFalse($builder->has('foo'), '->has() returns false if the service does not exist');
$builder->register('foo', 'Bar\FooClass');
$this->assertTrue($builder->has('foo'), '->has() returns true if a service definition exists');
$builder->set('bar', new \stdClass());
$this->assertTrue($builder->has('bar'), '->has() returns true if a service exists');
}