ValhallaRequest constructor
      
      ValhallaRequest({ 
    
    
- String? id,
- required List<LngLat> waypoints,
- List<LngLat> ? excludeLocations,
- List? excludePolygones,
- ValhallaDirectionsType directionsType = ValhallaDirectionsType.instructions,
- BaseCostingOption? costingOption,
- Costing costing = Costing.auto,
- ValhallaUnit units = ValhallaUnit.km,
- Languages languages = Languages.en,
- DateTime? time,
- ValhallaFormat valhallaFormat = ValhallaFormat.json,
- Geometries? valhallaShapeFormat,
- bool? bannerInstructions,
- bool? voiceInstructions,
- int alternatives = 2,
Implementation
ValhallaRequest({
  this.id,
  required super.waypoints,
  this.excludeLocations,
  this.excludePolygones,
  this.directionsType = ValhallaDirectionsType.instructions,
  this.costingOption,
  this.costing = Costing.auto,
  this.units = ValhallaUnit.km,
  super.languages,
  this.time,
  this.valhallaFormat = ValhallaFormat.json,
  this.valhallaShapeFormat,
  this.bannerInstructions,
  this.voiceInstructions,
  super.alternatives,
}) : assert(
       waypoints.length == 2,
       "we dont support more that 2 points for routing service for now",
     ),
     assert(
       languages != Languages.ar,
       "arabic language not supported for now",
     ),
     assert(
       (valhallaFormat == ValhallaFormat.orsm &&
               Geometries.values.contains(valhallaShapeFormat)) ||
           valhallaFormat != ValhallaFormat.orsm,
     );