BMFOpenNaviOption.fromMap constructor Null safety

Implementation

BMFOpenNaviOption.fromMap(Map map)
    : assert(
          map != null, //ignore: unnecessary_null_comparison
          'Construct a BMFOpenNaviOption，The parameter map cannot be null !'),
      assert(map.containsKey('startCoord')),
      assert(map.containsKey('endCoord')),
      assert(map.containsKey('naviType')) {
  startCoord = map['startCoord'] == null
      ? null
      : BMFCoordinate.fromMap(map['startCoord']);
  endCoord =
      map['endCoord'] == null ? null : BMFCoordinate.fromMap(map['endCoord']);
  startName = map['startName'];
  endName = map['endName'];
  naviType = map['naviType'] != null
      ? BMFNaviType.values[map['naviType'] as int]
      : null;
  appScheme = map['appScheme'];
  appName = map['appName'];
  isSupportWeb = map['isSupportWeb'] as bool?;
  preferenceType = map['preferenceType'] != null
      ? BMFNaviRoutePlanType.values[map['preferenceType'] as int]
      : null;
}