code: func assertNotExistsAndCreate(p string) []error {
  	var errs []error
  	errs = append(errs, assertNotExists(p)...)
  	if err := touchFile(p); err != nil {
  		errs = append(errs, fmt.Errorf("error touching file %q: %v", p, err))
  	}
  	return errs
  }
docs: // assertNotExistsAndCreate asserts that a file at the given path does not
  // exist, and then proceeds to create (touch) the file. It returns any errors
  // encountered at either of these steps.