protected function _emptyFolder()
{
self::$vfs->copy('test/dir1', 'file1', 'test/dir2');
self::$vfs->copy('test/dir1', 'file2', 'test/dir2');
self::$vfs->createFolder('test/dir2', 'dir2_1');
$this->assertEquals(array('dir2_1', 'dir5', 'file1', 'file2'), array_keys($this->_sort(self::$vfs->listFolder('test/dir2'))));
self::$vfs->emptyFolder('test/dir2');
$this->assertFalse(self::$vfs->exists('test/dir2', 'file1'));
$this->assertFalse(self::$vfs->exists('test/dir2', 'file2'));
$this->assertFalse(self::$vfs->exists('test/dir2', 'dir2_1'));
$this->assertTrue(self::$vfs->exists('test', 'dir2'));
$this->assertEquals(array(), self::$vfs->listFolder('test/dir2'));
}