println(
                "transferInitiated",
                message + ": " + event.getResource().getRepositoryUrl()
                        + event.getResource().getResourceName());
    }

    @Override
    public void transferProgressed(TransferEvent event) {
        TransferResource resource = event.getResource();
        downloads.put(resource, event.getTransferredBytes());

        Long transferred;
        synchronized (transfers) {
            transferred = transfers.remove(transferEvent.getResource());
        }
        if (transferred != null) {
            event.setTransferredBytes(transferred);
        }

        synchronized (artifacts) {
            artifacts.remove(transferEvent.getResource());
        }

        listener.transferCompleted(event);
    }

    @Override

  }

  public void testToString() throws IOException {
    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(I18N, Resources.toString(resource, UTF_8));
    assertThat(Resources.toString(resource, US_ASCII)).isNotEqualTo(I18N);
  }

  public void testToByteArray() throws IOException {
    URL resource = getClass().getResource("testdata/i18n.txt");

        ongoing.putIfAbsent(new TransferResourceIdentifier(event.getResource()), Boolean.TRUE);
        put(event, false);
    }

    @Override
    public void transferStarted(TransferEvent event) throws TransferCancelledException {
        if (ongoing.get(new TransferResourceIdentifier(event.getResource())) == Boolean.FALSE) {
            throw new TransferCancelledException();
        }

        String direction = event.getRequestType() == TransferEvent.RequestType.PUT ? "to" : "from";

        TransferResource resource = event.getResource();
        StringBuilder message = new StringBuilder();
        message.append(action).append(' ').append(direction).append(' ').append(resource.getRepositoryId());
        message.append(": ");

        String direction = event.getRequestType() == TransferEvent.RequestType.PUT ? "to" : "from";

        TransferResource resource = event.getResource();
        MessageBuilder message = messageBuilderFactory.builder();
        message.style(STYLE).append(action).append(' ').append(direction).append(' ');
        message.resetStyle().append(resource.getRepositoryId());

        ongoing.putIfAbsent(new TransferResourceIdentifier(event.getResource()), Boolean.TRUE);
        put(event, false);
    }

    @Override
    public void transferStarted(TransferEvent event) throws TransferCancelledException {
        if (ongoing.get(new TransferResourceIdentifier(event.getResource())) == Boolean.FALSE) {
            throw new TransferCancelledException();
        }

        String direction = event.getRequestType() == TransferEvent.RequestType.PUT ? "to" : "from";

        TransferResource resource = event.getResource();
        StringBuilder message = new StringBuilder();
        message.append(darkOn).append(action).append(' ').append(direction).append(' ');
        message.append(darkOff).append(resource.getRepositoryId());

        transfers.remove(new TransferResourceIdentifier(event.getResource()));
        overridePreviousTransfer(event);

        super.transferSucceeded(event);
    }

    @Override
    public void transferFailed(TransferEvent event) {
        transfers.remove(new TransferResourceIdentifier(event.getResource()));
        overridePreviousTransfer(event);

        super.transferFailed(event);

  // e.g. Optional<URL> tryGetResource or boolean resourceExists
  public static URL getResource(String resourceName) {
    ClassLoader loader =
        MoreObjects.firstNonNull(
            Thread.currentThread().getContextClassLoader(), Resources.class.getClassLoader());
    URL url = loader.getResource(resourceName);
    checkArgument(url != null, "resource %s not found.", resourceName);
    return url;
  }