Наследование: extends Kraken\Filesystem\FilesystemInterface
 /**
  * @dataProvider observableFilesystemManagerProvider
  */
 public function testApiEraseDir_ThrowsException_WhenFsDoesNotExist(FilesystemManagerInterface $man, ObjectProphecy $p1, ObjectProphecy $p2)
 {
     $this->setExpectedException(WriteException::class);
     $man->eraseDir('not_fs://path');
 }