How to use

emptyNavigableSet

method

in

java.util.Collections

 @Override
 public NavigableSet<String> create(String[] elements) {
  return Collections.emptyNavigableSet();
 }
})

 @Value.Default
 @Value.ReverseOrder
 default NavigableSet<Integer> navs() {
  return Collections.emptyNavigableSet();
 }
}

classes.add(Collections.checkedMap(Collections.emptyMap(), Void.class, Void.class).getClass());
classes.add(Collections.checkedNavigableMap(Collections.emptyNavigableMap(), Void.class, Void.class).getClass());
classes.add(Collections.checkedNavigableSet(Collections.emptyNavigableSet(), Void.class).getClass());
classes.add(Collections.checkedQueue(new LinkedList<>(), Void.class).getClass());
classes.add(Collections.checkedSet(Collections.emptySet(), Void.class).getClass());
classes.add(Collections.synchronizedMap(Collections.emptyMap()).getClass());
classes.add(Collections.synchronizedNavigableMap(Collections.emptyNavigableMap()).getClass());
classes.add(Collections.synchronizedNavigableSet(Collections.emptyNavigableSet()).getClass());
classes.add(Collections.synchronizedSet(Collections.emptySet()).getClass());
classes.add(Collections.synchronizedSortedMap(Collections.emptySortedMap()).getClass());
classes.add(Collections.unmodifiableMap(Collections.emptyMap()).getClass());
classes.add(Collections.unmodifiableNavigableMap(Collections.emptyNavigableMap()).getClass());
classes.add(Collections.unmodifiableNavigableSet(Collections.emptyNavigableSet()).getClass());
classes.add(Collections.unmodifiableSet(Collections.emptySet()).getClass());
classes.add(Collections.unmodifiableSortedMap(Collections.emptySortedMap()).getClass());

assertTrue(immutability.test(Collections.emptyMap()));
assertTrue(immutability.test(Collections.emptyNavigableMap()));
assertTrue(immutability.test(Collections.emptyNavigableSet()));
assertTrue(immutability.test(Collections.emptySet()));
assertTrue(immutability.test(Collections.emptySortedMap()));

 @Override
 public NavigableSet<String> create(String[] elements) {
  return Collections.emptyNavigableSet();
 }
})

public NavigableSet<Pair<Integer,Double>> getErrata(int codePoint){
  return erratas.getOrDefault(codePoint,Collections.emptyNavigableSet());
}
public static ErrataList generate(Iterator<Pair<Integer,ConnectedComponent>> iterator,CharacterRecognizer recognizer,long support,double threhold){

  @Override
  public NavigableSet<Integer> getStartedRemotePortForwards() {
    synchronized (remoteToLocal) {
      if (remoteToLocal.isEmpty()) {
        return Collections.emptyNavigableSet();
      }

      return GenericUtils.asSortedSet(remoteToLocal.keySet());
    }
  }
}

@Override
public NavigableSet<Integer> getStartedLocalPortForwards() {
  synchronized (localToRemote) {
    if (localToRemote.isEmpty()) {
      return Collections.emptyNavigableSet();
    }
    return GenericUtils.asSortedSet(localToRemote.keySet());
  }
}

  @Override
  public NavigableSet<Integer> getStartedRemotePortForwards() {
    synchronized (remoteToLocal) {
      if (remoteToLocal.isEmpty()) {
        return Collections.emptyNavigableSet();
      }

      return GenericUtils.asSortedSet(remoteToLocal.keySet());
    }
  }
}

@Override
public NavigableSet<Integer> getStartedLocalPortForwards() {
  synchronized (localToRemote) {
    if (localToRemote.isEmpty()) {
      return Collections.emptyNavigableSet();
    }
    return GenericUtils.asSortedSet(localToRemote.keySet());
  }
}

@Override
public NavigableSet<Integer> getStartedRemotePortForwards() {
  ForwardingFilter filter = getForwardingFilter();
  return (filter == null) ? Collections.emptyNavigableSet() : filter.getStartedRemotePortForwards();
}

@Override
public NavigableSet<Integer> getStartedLocalPortForwards() {
  ForwardingFilter filter = getForwardingFilter();
  return (filter == null) ? Collections.emptyNavigableSet() : filter.getStartedLocalPortForwards();
}

@Override
public NavigableSet<Integer> getStartedRemotePortForwards() {
  ForwardingFilter filter = getForwardingFilter();
  return (filter == null) ? Collections.emptyNavigableSet() : filter.getStartedRemotePortForwards();
}

/**
 * Build a data structure that to optimize checking whether a field in an object type is being monitored.
 */
private synchronized NavigableSet<Long> buildHasFieldMonitorCache() {
  if (this.monitorMap == null)
    return Collections.emptyNavigableSet();
  final TreeSet<Long> set = new TreeSet<>();
  for (Schema otherSchema : this.schemas.versions.values()) {
    for (ObjType objType : otherSchema.objTypeMap.values()) {
      final int objTypeStorageId = objType.storageId;
      for (Field<?> field : objType.fieldsAndSubFields) {
        final int fieldStorageId = field.storageId;
        final Set<FieldMonitor> monitors = this.getMonitorsForField(fieldStorageId);
        if (monitors != null && monitors.stream().anyMatch(new MonitoredPredicate(objTypeStorageId, fieldStorageId)))
          set.add(this.buildHasFieldMonitorCacheKey(objTypeStorageId, fieldStorageId));
      }
    }
  }
  return set;
}

@Override
public NavigableSet<Integer> getStartedLocalPortForwards() {
  ForwardingFilter filter = getForwardingFilter();
  return (filter == null) ? Collections.emptyNavigableSet() : filter.getStartedLocalPortForwards();
}

public HTTP2ServerBuilder httpServer(SimpleHTTPServerConfiguration serverConfiguration,
                   HTTPBodyConfiguration httpBodyConfiguration) {
  AbstractErrorResponseHandler handler = DefaultErrorResponseHandlerLoader.getInstance().getHandler();
  server = new SimpleHTTPServer(serverConfiguration);
  server.badMessage((status, reason, request) -> {
    RoutingContext ctx = new RoutingContextImpl(request, Collections.emptyNavigableSet());
    handler.render(ctx, status, new BadMessageException(reason));
  });
  routerManager = RouterManager.create(httpBodyConfiguration);
  return this;
}

public HTTP2ServerBuilder httpServer(SimpleHTTPServerConfiguration serverConfiguration,
                   HTTPBodyConfiguration httpBodyConfiguration) {
  AbstractErrorResponseHandler handler = DefaultErrorResponseHandlerLoader.getInstance().getHandler();
  server = new SimpleHTTPServer(serverConfiguration);
  server.badMessage((status, reason, request) -> {
    RoutingContext ctx = new RoutingContextImpl(request, Collections.emptyNavigableSet());
    handler.render(ctx, status, new BadMessageException(reason));
  });
  routerManager = RouterManager.create(httpBodyConfiguration);
  return this;
}

@Test
public void readPost111() throws IOException {
  String prefix = "post-1.1.1-";
  assertCollectionEqualAndUsable(Collections.emptyList(), readFileAndDeserialize(prefix + "emptyList"));
  assertCollectionEqualAndUsable(Arrays.asList("test"), readFileAndDeserialize(prefix + "asList"));
  assertCollectionEqualAndUsable(Collections.emptyMap(), readFileAndDeserialize(prefix + "emptyMap"));
  assertCollectionEqualAndUsable(Collections.emptyNavigableMap(),
      readFileAndDeserialize(prefix + "emptyNavigableMap"));
  assertCollectionEqualAndUsable(Collections.emptySortedMap(), readFileAndDeserialize(prefix + "emptySortedMap"));
  assertCollectionEqualAndUsable(Collections.emptySet(), readFileAndDeserialize(prefix + "emptySet"));
  assertCollectionEqualAndUsable(Collections.emptyNavigableSet(),
      readFileAndDeserialize(prefix + "emptyNavigableSet"));
  assertCollectionEqualAndUsable(Collections.emptySortedSet(), readFileAndDeserialize(prefix + "emptySortedSet"));
  assertCollectionEqualAndUsable(Collections.singleton("test"), readFileAndDeserialize(prefix + "singletonSet"));
  assertCollectionEqualAndUsable(Collections.singletonList("test"),
      readFileAndDeserialize(prefix + "singletonList"));
  assertCollectionEqualAndUsable(Collections.singletonMap("k", "v"),
      readFileAndDeserialize(prefix + "singletonMap"));
}

@Test
public void testEmptyCollectionSerialization() {
  Object target;
  target = Collections.emptyList();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptySet();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptyMap();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptyNavigableMap();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptyNavigableSet();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptySortedMap();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
  target = Collections.emptySortedSet();
  assertCollectionEqualAndUsable(target, serAndDeser(target));
}

@Test
public void testEmptyCollectionClone() {
  Object target;
  target = Collections.emptyList();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptySet();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptyMap();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptyNavigableMap();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptyNavigableSet();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptySortedMap();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
  target = Collections.emptySortedSet();
  assertCollectionEqualAndUsable(target, cloneWithKryo(target));
}