checkFollowing method
Check if current user follow the provided FollowingType.artists or FollowingType.users.
Returns the list of ids
mapped with the response whether it has been
followed or not
Implementation
Future<Map<String, bool>> checkFollowing(
FollowingType type, List<String> ids) async {
assert(ids.isNotEmpty, 'No user/artist id was provided');
final jsonString =
await _api._get('$_path/following/contains?${_buildQuery({
'type': type._key,
'ids': ids.join(','),
})}');
final list = List.castFrom<dynamic, bool>(json.decode(jsonString));
return Map.fromIterables(ids, list);
}