NSMutableArray *list = [[NSMutableArray alloc] init];
NSPredicate *bobPredicate = [NSPredicate predicateWithFormat:@"ObjectId in %@",@[@"id2",@"id4",@"id1"]];
[list filteredArrayUsingPredicate:predicate];

  for (NSManagedObject * test in list) {
      [test setValue:@"test" forKey:@"name"];
  }