@Override
  public FileLock tryLock(long position, long size, boolean shared) throws IOException {
    Util.checkNotNegative(position, "position");
    Util.checkNotNegative(size, "size");
    channel.checkOpen();
    if (shared) {
      channel.checkReadable();
    } else {
      channel.checkWritable();
    }
    return new JimfsFileChannel.FakeFileLock(this, position, size, shared);
  }
{@link AsynchronousFileChannel} implementation that delegates to a {@link JimfsFileChannel}.

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