PartNumber          int                 // only useful in case of GetObject/HeadObject
	CheckPrecondFn      CheckPreconditionFn // only set during GetObject/HeadObject/CopyObjectPart preconditional valuation
	EvalMetadataFn      EvalMetadataFn      // only set for retention settings, meant to be used only when updating metadata in-place.

const (
	putObjectTaggingAPI    replProxyAPI = "PutObjectTagging"
	getObjectTaggingAPI    replProxyAPI = "GetObjectTagging"
	removeObjectTaggingAPI replProxyAPI = "RemoveObjectTagging"
	headObjectAPI          replProxyAPI = "HeadObject"
	getObjectAPI           replProxyAPI = "GetObject"
)

// ProxyMetric holds stats for replication proxying
type ProxyMetric struct {
	PutTagTotal       uint64 `json:"putTaggingProxyTotal" msg:"ptc"`

			t := router.Methods(r.methods...).
				HandlerFunc(collectAPIStats(r.api, httpTraceAll(notImplementedHandler))).
				Queries(r.queries...)
			t.Path(r.path)
		}

		// Object operations
		// HeadObject
		router.Methods(http.MethodHead).Path("/{object:.+}").
			HandlerFunc(s3APIMiddleware(api.HeadObjectHandler))

		// GetObjectAttributes
		router.Methods(http.MethodGet).Path("/{object:.+}").

  @J2ktIncompatible
  // Serialization type safety is at the caller's mercy.
  @SuppressWarnings("unchecked")
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    Comparator<Object> valueComparator = (Comparator<Object>) stream.readObject();
    int keyCount = stream.readInt();
    if (keyCount < 0) {

      Object key = requireNonNull(stream.readObject());
      int valueCount = stream.readInt();
      if (valueCount <= 0) {
        throw new InvalidObjectException("Invalid value count " + valueCount);
      }

      ImmutableList.Builder<Object> valuesBuilder = ImmutableList.builder();
      for (int j = 0; j < valueCount; j++) {
        valuesBuilder.add(requireNonNull(stream.readObject()));
      }

  @J2ktIncompatible
  // Serialization type safety is at the caller's mercy.
  @SuppressWarnings("unchecked")
  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    Comparator<Object> valueComparator = (Comparator<Object>) stream.readObject();
    int keyCount = stream.readInt();
    if (keyCount < 0) {

      @SuppressWarnings("unchecked")
      K key = (K) stream.readObject();
      map.put(key, createCollection(key));
    }
    int entries = stream.readInt();
    for (int i = 0; i < entries; i++) {
      @SuppressWarnings("unchecked")
      K key = (K) stream.readObject();
      @SuppressWarnings("unchecked")
      V value = (V) stream.readObject();
      /*

      Object key = requireNonNull(stream.readObject());
      int valueCount = stream.readInt();
      if (valueCount <= 0) {
        throw new InvalidObjectException("Invalid value count " + valueCount);
      }

      ImmutableList.Builder<Object> valuesBuilder = ImmutableList.builder();
      for (int j = 0; j < valueCount; j++) {
        valuesBuilder.add(requireNonNull(stream.readObject()));
      }

    }
    init(elementCount);
    for (int i = 0; i < elementCount; i++) {
      K key = (K) stream.readObject();
      V value = (V) stream.readObject();
      put(key, value);
    }
  }

  /*
   * The following methods are safe to call as long as both of the following hold:
   *
   * - allocArrays() has been called. Callers can confirm this by checking needsAllocArrays().
   *

    @Override
    protected void parse(final byte[] token) throws IOException {

        try (ASN1InputStream is = new ASN1InputStream(token)) {
            final ASN1TaggedObject constructed = (ASN1TaggedObject) is.readObject();
            if (constructed == null || constructed.getTagClass() != BERTags.APPLICATION
                    || !(constructed.getBaseObject() instanceof ASN1Sequence)) {