### Question:
NatService { public String queryLocalIPAddress(final String fallbackValue) throws RuntimeException { if (isNatEnvironment()) { try { final NatManager natManager = getNatManager().orElseThrow(); LOG.debug( "Waiting for up to {} seconds to detect local IP address...", NatManager.TIMEOUT_SECONDS); return Optional.ofNullable( natManager.queryLocalIPAddress().get(NatManager.TIMEOUT_SECONDS, TimeUnit.SECONDS)) .orElseThrow(); } catch (Exception e) { LOG.debug("Caught exception while trying to query NAT local IP address (ignoring)", e); LOG.warn( "Unable to query NAT local IP address. Using the fallback value : {} ", fallbackValue); } } return fallbackValue; } NatService(final Optional<NatManager> natManager, final boolean fallbackEnabled);  NatService(final Optional<NatManager> natManager); boolean isNatEnvironment(); void ifNatEnvironment(
      final NatMethod natMethod, final Consumer<? super NatManager> action); NatMethod getNatMethod(); Optional<NatManager> getNatManager(); void start(); void stop(); String queryExternalIPAddress(final String fallbackValue); String queryLocalIPAddress(final String fallbackValue); Optional<NatPortMapping> getPortMapping(
      final NatServiceType serviceType, final NetworkProtocol networkProtocol); static NatMethod autoDetectNatMethod(final NatMethodDetector... natMethodDetectors);  }### Answer:
@Test public void assertThatQueryLocalIPAddressWorksProperlyWithoutNat() { final String fallbackValue = "1.2.3.4"; final NatService natService = new NatService(Optional.empty(), true); final String resultIp = natService.queryLocalIPAddress(fallbackValue); assertThat(resultIp).isEqualTo(fallbackValue); }