sink.writeFrom(new ByteArrayInputStream(data));

    assertContainsExpectedBytes();
  }

  private void assertContainsExpectedBytes() throws IOException {
    assertArrayEquals(expected, factory.getSinkContents());
  }

    sink.writeFrom(new ByteArrayInputStream(data));

    assertContainsExpectedBytes();
  }

  private void assertContainsExpectedBytes() throws IOException {
    assertArrayEquals(expected, factory.getSinkContents());
  }

  public interface SinkFactory<S, T> extends SourceSinkFactory<S, T> {

    /** Creates a new sink. */
    S createSink() throws IOException;

    /** Gets the current content of the created sink. */
    T getSinkContents() throws IOException;
  }

  /** Factory for {@link ByteSource} instances. */
  public interface ByteSourceFactory extends SourceFactory<ByteSource, byte[]> {}

  /** Factory for {@link ByteSink} instances. */