PppoeClientManager { public Collection<PppoeClientInfo> getClients(String ssid) { if (ssid == null) { return ImmutableList.copyOf(clients.values()); } PppoeClientInfo clientInfo = clients.get(ssid); if (clientInfo == null) { return Collections.emptyList(); } List<PppoeClientInfo> clientList = new ArrayList<PppoeClientInfo>(); clientList.add(clientInfo); return clientList; } PppoeClientManager(DeviceService deviceService, DriverService driverService,
                              MastershipService mastershipService, AccessDeviceService accessDeviceService); boolean configClient(String ssid, String paramName, String paramValue); Collection<PppoeClientInfo> getClients(String ssid); Collection<PppoeSessionInfo> getSessions(); void addClient(PppoeDeviceInfo deviceInfo); void removeClient(PppoeDeviceInfo deviceInfo);  }
@Test public void testgetClientsRestServerNotExist() throws Exception { assertEquals("Incorrect response", 0, clientManager.getClients(null).size()); assertEquals("Incorrect response", 0, clientManager.getClients(ssid).size()); }