code: func appendOptionsList(opts []*unit.UnitOption, section, property, prefix string, vals ...string) []*unit.UnitOption {
  	for _, v := range vals {
  		opts = append(opts, unit.NewUnitOption(section, property, fmt.Sprintf("%s%s", prefix, v)))
  	}
  	return opts
  }
docs: // appendOptionsList updates an existing unit options list appending
  // an array of new properties, one entry at a time.
  // This is the preferred method to avoid hitting line length limits
  // in unit files. Target property must support multi-line entries.