code: func (t RefType) Prefix() (string, bool) {
  	switch t {
  	case RefTypeLocalBranch:
  		return "refs/heads", true
  	case RefTypeRemoteBranch:
  		return "refs/remotes", true
  	case RefTypeLocalTag:
  		return "refs/tags", true
  	default:
  		return "", false
  	}
  }
docs: // Prefix returns the given RefType's prefix, "refs/heads", "ref/remotes",
  // etc. It returns an additional value of either true/false, whether or not this
  // given ref type has a prefix.
  //
  // If the RefType is unrecognized, Prefix() will panic.