exists method
Check if a document exists
Implementation
Future<bool> exists(String index, String collection, String id) async {
final response = await kuzzle.query(KuzzleRequest(
controller: name,
action: 'exists',
index: index,
collection: collection,
uid: id,
));
if (response.result is bool) {
return response.result as bool;
}
throw BadResponseFormatError(
response.error?.id, '$name.exists: bad response format', response);
}