code: func FileToSliceUnmerged(path string) ([][][]string, error) {
  	f, err := OpenFile(path)
  	if err != nil {
  		return nil, err
  	}
  	return f.ToSliceUnmerged()
  }
docs: // FileToSliceUnmerged is a wrapper around File.ToSliceUnmerged.
  // It returns the raw data contained in an Excel XLSX file as three
  // dimensional slice. Merged cells will be unmerged. Covered cells become the
  // values of theirs origins.