this.listener = listener;
        this.artifacts = new IdentityHashMap<>();
        this.transfers = new IdentityHashMap<>();
    }

    public void debug(String message) {}

    public void transferCompleted(TransferEvent transferEvent) {
        ArtifactTransferEvent event = wrap(transferEvent);

        Long transferred;
        synchronized (transfers) {

    void transferInitiated(ArtifactTransferEvent transferEvent);

    void transferStarted(ArtifactTransferEvent transferEvent);

    void transferProgress(ArtifactTransferEvent transferEvent);

    void transferCompleted(ArtifactTransferEvent transferEvent);