def get_complete_testing_sets(playlists, test_indices_dict):
    """
    Generates dictionary with test buckets according to provided indices. 
    Adds additional seed and groundtruth lists to playlists.
    
    Parameters:
    --------------
    playlists:         list, original playlists included in test set
    test_indices_dict: dict, dictionary including the indices for every split
    
    Returns:
    --------------
    return_dict:       dict, {bucket_no: [playlist1, playlist2, ..., playlistn], ...}
    """
    # prepare return_dict
    return_dict = {}
    for bucket in test_indices_dict.keys():
        return_dict[bucket] = [y for x, y in enumerate(playlists) if x in test_indices_dict[bucket]]
    
    # add seed tracks and ground_truth to playlists
    for key in return_dict.keys():
        for playlist in return_dict[key]:
            playlist['seed'] = [x for x in playlist['tracks'][:key]]
            playlist['groundtruth'] = [x for x in playlist['tracks'][key:]]
    
    return return_dict