BMFOpenRouteOption.fromMap constructor Null safety

Implementation

BMFOpenRouteOption.fromMap(Map map)
    : assert(
          map != null, //ignore: unnecessary_null_comparison
          'Construct a BMFOpenRouteOption，The parameter map cannot be null !'),
      assert(map.containsKey('startCoord')),
      assert(map.containsKey('endCoord')),
      assert(map.containsKey('routeTyp')) {
  startCoord = map['startCoord'] != null
      ? BMFCoordinate.fromMap(map['startCoord'])
      : null;
  endCoord =
      map['endCoord'] != null ? BMFCoordinate.fromMap(map['endCoord']) : null;
  startName = map['startName'];
  endName = map['endName'];
  routeType = map['routeType'] != null
      ? BMFOpenRouteType.values[map['routeType'] as int]
      : null;
  transitPolicy = map['transitPolicy'] != null
      ? BMFOpenTransitPolicy.values[(map['transitPolicy'] as int) - 3]
      : null;
  appScheme = map['appScheme'];
  isSupportWeb = map['isSupportWeb'] as bool?;
}