code: func (d Direction) Friendly() string {
  	switch d {
  	case DirectionOutboundReply:
  		return "Reply"
  	case DirectionOutboundCall:
  		return "Outgoing (from call)"
  	case DirectionOutboundAPI:
  		return "Outgoing (from API)"
  	case DirectionInbound:
  		return "Incoming"
  	case DirectionOutboundDial:
  		return "Outgoing (via Dial)"
  	case DirectionTrunkingTerminating:
  		return "Trunking (terminating)"
  	case DirectionTrunkingOriginating:
  		return "Trunking (originating)"
  	default:
  		return string(d)
  	}
  }
docs: // Friendly prints out a friendly version of the Direction, following the
  // example shown in the Twilio Dashboard.