protected function _size()
{
$this->assertEquals(8, self::$vfs->size('test', 'file1'));
$this->assertEquals(10, self::$vfs->size('test/dir1', 'file1'));
$this->assertEquals(10, self::$vfs->size('test/dir3', 'file1'));
$this->assertEquals(filesize(__FILE__), self::$vfs->size('test/dir1', 'file2'));
$this->assertEquals(filesize(__FILE__), self::$vfs->size('test/dir3', 'file2', __FILE__));
}