How to use the fd-slicer.createFromFd function in fd-slicer

fs.open(localFile, 'r', function(err, fd) {
      if (err) return handleError(err);
      localFileSlicer = fd_slicer.createFromFd(fd, {autoClose: true});
      localFileSlicer.on('error', handleError);
      localFileSlicer.on('close', function() {
        uploader.emit('fileClosed');
      });

      // keep an extra reference alive until we decide that we're completely
      // done with the file
      localFileSlicer.ref();

      uploader.emit('fileOpened', localFileSlicer);

      fs.fstat(fd, function(err, stat) {
        if (err) return handleError(err);
        localFileStat = stat;
        uploader.progressTotal = stat.size;
        startPuttingObject();

fs.open(publicFile.path, 'wx', function(err, fd) {
    if (err) return self.handleError(err);
    var slicer = fdSlicer.createFromFd(fd, {autoClose: true});

    // end option here guarantees that no more than that amount will be written
    // or else an error will be emitted
    internalFile.ws = slicer.createWriteStream({end: self.maxFilesSize - self.totalFileSize});

    // if an error ocurred while we were waiting for fs.open we handle that
    // cleanup now
    self.openedFiles.push(internalFile);
    if (self.error) return cleanupOpenFiles(self);

    var prevByteCount = 0;
    internalFile.ws.on('error', function(err) {
      self.handleError(err.code === 'ETOOBIG'
        ? createError(413, err.message, { code: err.code })
        : err)
    });

fs.open(publicFile.path, 'wx', function(err, fd) {
    if (err) return self.handleError(err);
    var slicer = fdSlicer.createFromFd(fd, {autoClose: true});

    // end option here guarantees that no more than that amount will be written
    // or else an error will be emitted
    internalFile.ws = slicer.createWriteStream({end: self.maxFilesSize - self.totalFileSize});

    // if an error ocurred while we were waiting for fs.open we handle that
    // cleanup now
    self.openedFiles.push(internalFile);
    if (self.error) return cleanupOpenFiles(self);

    var prevByteCount = 0;
    internalFile.ws.on('error', function(err) {
      self.handleError(err.code === 'ETOOBIG'
        ? createError(413, err.message, { code: err.code })
        : err)
    });

fs.fstat(fd, function(err, stats) {
    if (err) return callback(err);
    var reader = fd_slicer.createFromFd(fd, {autoClose: true});
    fromRandomAccessReader(reader, stats.size, options, callback);
  });
}

fs.fstat(fd, function(err, stats) {
    if (err) return callback(err);
    var reader = fd_slicer.createFromFd(fd, {autoClose: true});
    fromRandomAccessReader(reader, stats.size, options, callback);
  });
}

fs.fstat(fd, function(err, stats) {
    if (err) return callback(err);
    var reader = fd_slicer.createFromFd(fd, {autoClose: true});
    fromRandomAccessReader(reader, stats.size, options, callback);
  });
}

fs.fstat(fd, function(err, stats) {
    if (err) return callback(err);
    var reader = fd_slicer.createFromFd(fd, {autoClose: true});
    fromRandomAccessReader(reader, stats.size, options, callback);
  });
}

fs.open(filePath, 'r', (err, fd) => {
        try {
          if (err) {
            throw err
          }
          resolve(FdSlicer.createFromFd(fd))
        } catch (error) {
          reject({
            error,
            trace: 'CosRandomAccessReader.getFdSlicer'
          })
        }
      })
    })