test.m

    NSError *error;
    CDTDatastoreManager *manager = [[CDTDatastoreManager alloc] initWithDirectory:@"/tmp" error:&error];
    CDTDatastore *store = [manager datastoreNamed:@"my_ds" error:&error];
    CDTDocumentRevision *rev = [CDTDocumentRevision revision];
    rev.body = [@{ @"hello" : @"world" } mutableCopy];
    [store createDocumentFromRevision:rev error:&error];
    [store ensureIndexed:@[@"hello"]];
    NSLog(@"Indexes: %@", [store listIndexes]);