public function getMatchingEntries()
    {
        if ($this->matchingEntries === null) {
            $this->matchingEntries = array();
            foreach ($this->entries as $entry) {
                $this->matchingEntries = array_merge($this->matchingEntries, $entry->getMatchingEntries());
            }
        }

        return $this->matchingEntries;
    }