def get_group_reviews(revs, group_rev_indxs, group_rev_indxs_mask):
    """For each group returns its input reviews considering masking."""
    coll = []
    for indxs, mask in zip(group_rev_indxs, group_rev_indxs_mask):
        coll.append([revs[indx] for indx, m in zip(indxs, mask) if m != 0])
    return coll