@Test
    void testLocalhostAddressCanBeUsed() {
        final Collection<ServerPort> serverPorts = server.activePorts().values();
        assertThat(serverPorts).hasSize(1);
        for (ServerPort sp : serverPorts) {
            final InetAddress address = sp.localAddress().getAddress();
            assertThat(address.isLoopbackAddress()).isTrue();
        }
    }
Tests for keeping the behavior of {@link Port#getIp()}.
spring/boot2-autoconfigure/src/test/java/com/linecorp/armeria/spring/LocalhostAddressTest.java