### Question:
HostPort { public String getHostPort() { return host + "_" + port; } HostPort(String host, int port); String getHost(); int getPort(); String getHostPort(); static HostPort parseHostPort(String string);  }### Answer:
@Test public void testGetHostPort() { HostPort hostPort = new HostPort("127.0.0.1", 2183); assertTrue(hostPort.getHostPort().equals("127.0.0.1_2183")); }