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);
  }

  @GwtIncompatible // not needed in emulated source.

    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);
  }

  @GwtIncompatible // not needed in emulated source.

    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 {

    @Inject
    SwitchableMetadataSource switchableMetadataSource;

    @BeforeEach
    void setup() throws CycleDetectedInComponentGraphException {
        switchableMetadataSource.setDelegate(defaultMetadataSource);
    }