truncate method
Empties a collection
by removing all its documents,
while keeping any associated mapping
Implementation
Future<Map<String, dynamic>> truncate(String index, String collection) async {
final response = await kuzzle.query(KuzzleRequest(
controller: name,
action: 'truncate',
index: index,
collection: collection,
));
return response.result as Map<String, dynamic>;
}