channel_1.send("test_1");
assertEquals(1, TestChannel.count);
Channel channel_2 = channel_map.get("channel_2");
assertNotNull(channel_2);
channel_2.send("test_2");
assertEquals(4, TestChannel.count);
Channel channel_3 = channel_map.get("channel_3");
assertNotNull(channel_3);
assertTrue(channel_3 instanceof ServiceChannel);