Status AuthzManagerExternalStateMock::_queryVector(
            const NamespaceString& collectionName,
            const BSONObj& query,
            std::vector<BSONObjCollection::iterator>* result) {

        StatusWithMatchExpression parseResult = MatchExpressionParser::parse(query);
        if (!parseResult.isOK()) {
            return parseResult.getStatus();
        }
        MatchExpression* matcher = parseResult.getValue();

        NamespaceDocumentMap::iterator mapIt = _documents.find(collectionName);
        if (mapIt == _documents.end())
            return Status(ErrorCodes::NoMatchingDocument,
                          "No collection named " + collectionName.ns());

        for (BSONObjCollection::iterator vecIt = mapIt->second.begin();
             vecIt != mapIt->second.end();
             ++vecIt) {

            if (matcher->matchesBSON(*vecIt)) {
                result->push_back(vecIt);
            }
        }
        return Status::OK();
    }
    Status AuthzManagerExternalStateMock::_findUser(const std::string& usersNamespace,
                                                    const BSONObj& query,
                                                    BSONObj* result) const {
        StatusWithMatchExpression parseResult = MatchExpressionParser::parse(query);
        if (!parseResult.isOK()) {
            return parseResult.getStatus();
        }
        MatchExpression* matcher = parseResult.getValue();

        unordered_map<std::string, std::vector<BSONObj> >::const_iterator mapIt;
        for (mapIt = _userDocuments.begin(); mapIt != _userDocuments.end(); ++mapIt) {
            for (std::vector<BSONObj>::const_iterator vecIt = mapIt->second.begin();
                    vecIt != mapIt->second.end(); ++vecIt) {
                if (nsToDatabase(usersNamespace) == mapIt->first &&
                        matcher->matchesBSON(*vecIt)) {
                    *result = *vecIt;
                    return Status::OK();
                }
            }
        }
        return Status(ErrorCodes::UserNotFound, "User not found");
    }