protected function _readByteRange()
{
$offset = 1;
$this->assertEquals('on', self::$vfs->readByteRange('test', 'file1', $offset, 2, $remain));
$this->assertEquals(3, $offset);
$this->assertEquals(5, $remain);
$offset++;
$this->assertEquals('en', self::$vfs->readByteRange('test', 'file1', $offset, 2, $remain));
$this->assertEquals(6, $offset);
$this->assertEquals(2, $remain);
$this->assertEquals('t1', self::$vfs->readByteRange('test', 'file1', $offset, -1, $remain));
}