protected function _read()
{
$this->assertEquals('content1', self::$vfs->read('test', 'file1'));
$this->assertEquals('content1_1', self::$vfs->read('test/dir1', 'file1'));
$this->assertEquals('content3_1', self::$vfs->read('test/dir3', 'file1'));
$this->assertEquals(file_get_contents(__FILE__), self::$vfs->read('test/dir1', 'file2'));
$this->assertEquals(file_get_contents(__FILE__), self::$vfs->read('test/dir3', 'file2', __FILE__));
}