public function entries()
    {
        $entries = array();

        if (false === $this->_entry_cache) {
            // cache is empty: fetch from LDAP
            while ($entry = $this->shiftEntry()) {
                $entries[] = $entry;
            }
            $this->_entry_cache = $entries; // store result in cache
        }

        return $this->_entry_cache;
    }