code: func (ms *FileMsgStore) closeLockedFiles(fslice *fileSlice) error {
  	err := ms.fm.closeLockedFile(fslice.file)
  	if idxErr := ms.fm.closeLockedFile(fslice.idxFile); idxErr != nil && err == nil {
  		err = idxErr
  	}
  	return err
  }
docs: // closeLockedFiles (unlocks and) closes the files of the given file slice.