public function read($len = null)
    {
        if (!$this->getInitialized()) {
            $this->_initialize();
            $this->setInitialized(true);
        }

        $buffer = $this->in->read($len);

        if ($buffer === -1) {
            return -1;
        }

        $buffer = str_replace("\t", str_repeat(' ', $this->tabLength), $buffer);

        return $buffer;
    }