@Override
  @CanIgnoreReturnValue
  public AsynchronousFileChannel truncate(long size) throws IOException {
    channel.truncate(size);
    return this;
  }
{@link AsynchronousFileChannel} implementation that delegates to a {@link JimfsFileChannel}.

@author Colin Decker
jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java