public function userSolvedProblems($users)
    {
        if (is_array($users) === false) {
            $users = array($users);
        }
        $rawSolved = $this->load('solved-bits', array($users));
        $users = array();

        foreach ($rawSolved as $user) {
            $users[$user['uid']] = $user['solved'];
        }

        return $users;
    }