#vulnerable code 
                                @Override
    public User getWithNetworksById(long id) {
        User user = find(id);

        Set<Long> networkIds = userNetworkDao.findNetworksForUser(id);
        Set<Network> networks = new HashSet<>();
        for (Long networkId : networkIds) {
            Network network = networkDao.find(networkId);
            networks.add(network);
        }
        user.setNetworks(networks);
        return user;
    } 
                            #location 7 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public User getWithNetworksById(long id) {
        User user = find(id);

        Set<Long> networkIds = userNetworkDao.findNetworksForUser(id);
        if (networkIds == null) {
            return user;
        }
        Set<Network> networks = new HashSet<>();
        for (Long networkId : networkIds) {
            Network network = networkDao.find(networkId);
            networks.add(network);
        }
        user.setNetworks(networks);
        return user;
    }