* the number of entries in the map, as that makes it easy for hostile inputs to trigger lots of
     * allocation—not that any program should be deserializing hostile inputs to begin with!)
     */
    setDelegates(new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new HashMap<V, K>());
    Serialization.populateMap(this, stream);
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

    stream.defaultReadObject();
    keyTypeOrObjectUnderJ2cl = (Class<K>) requireNonNull(stream.readObject());
    valueTypeOrObjectUnderJ2cl = (Class<V>) requireNonNull(stream.readObject());
    setDelegates(
        new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new EnumMap<V, K>(valueTypeOrObjectUnderJ2cl));
    Serialization.populateMap(this, stream);
  }

    private ArtifactMetadataSource delegate;

    @Inject
    public SwitchableMetadataSource(@Named("test") ArtifactMetadataSource delegate) {
        this.delegate = delegate;
    }

    public void setDelegate(ArtifactMetadataSource delegate) {
        this.delegate = delegate;
    }

    @Override
    public ResolutionGroup retrieve(MetadataResolutionRequest request) throws ArtifactMetadataRetrievalException {