@CanIgnoreReturnValue
  public boolean cancel(boolean mayInterruptIfRunning) {
    logger.get().log(FINER, "cancelling {0}", this);
    boolean cancelled = future.cancel(mayInterruptIfRunning);
    if (cancelled) {
      close();
    }
    return cancelled;
  }

  private void close() {
    logger.get().log(FINER, "closing {0}", this);
    closeables.close();
  }

  @CanIgnoreReturnValue
  public boolean cancel(boolean mayInterruptIfRunning) {
    logger.get().log(FINER, "cancelling {0}", this);
    boolean cancelled = future.cancel(mayInterruptIfRunning);
    if (cancelled) {
      close();
    }
    return cancelled;
  }

  private void close() {
    logger.get().log(FINER, "closing {0}", this);
    closeables.close();
  }

    static {

        try {
            Class.forName( "jcifs.smb1.Config" );
        } catch( ClassNotFoundException cnfe ) {
            cnfe.printStackTrace();
        }
        attrExpirationPeriod = Config.getLong( "jcifs.smb1.smb.client.attrExpirationPeriod", DEFAULT_ATTR_EXPIRATION_PERIOD );
        ignoreCopyToException = Config.getBoolean( "jcifs.smb1.smb.client.ignoreCopyToException", true );
        dfs = new Dfs();
    }