public function addAuthorMap($mapping)
    {
        foreach ($mapping as $author => $aliases) {
            if (\is_array($aliases)) {
                foreach ($aliases as $alias) {
                    $this->aliasAuthor($alias, $author);
                }
            } else {
                $this->aliasAuthor($aliases, $author);
            }
        }

        return $this;
    }