### Question:
ServerLobby { public synchronized RobotProxy getRobotProxy(String identifier) { for(RobotProxy robot : robots) { if(robot.getIdentifier().equals(identifier)) { return robot; } } return null; } ServerLobby(String serverName, int maxRobots, int maxUsers); synchronized void addLobbyStateListener(ServerLobbyListener listener); synchronized void removeLobbyStateListener(ServerLobbyListener listener); synchronized boolean addUserProxy(UserProxy userProxy); synchronized void removeUserProxy(UserProxy userProxy); synchronized boolean registerRobot(RobotProxy robot); synchronized void unregisterRobot(RobotProxy robot); synchronized void broadcastMessage(String message); synchronized void broadcastUserStateUpdate(UserProxy userProxy); synchronized void setGameType(GameType newType); boolean gameInProgress(); GameController getCurrentGame(); GameType getCurrentGameType(); synchronized RobotProxy getRobotProxy(String identifier); synchronized boolean isUsernameRegistered(String username); String getServerName(); synchronized void launchGame(); synchronized void endCurrentGame();  }### Answer:
@Test public void testGetRobotProxy() { RobotProxy testRobot = new TestRobotProxy(testLobby, "Registered"); assertEquals(null, testLobby.getRobotProxy("NotRegistered")); assertEquals(testRobot, testLobby.getRobotProxy("Registered")); assertEquals(null, testLobby.getRobotProxy(null)); }