def METHOD_NAME(self, gt_unit_id1, gt_unit_id2, bins):
    score_label1, score_label2, delta = self.get_label_for_collision(gt_unit_id1, gt_unit_id2)
    tp_count1 = np.zeros(bins.size - 1)
    fn_count1 = np.zeros(bins.size - 1)
    tp_count2 = np.zeros(bins.size - 1)
    fn_count2 = np.zeros(bins.size - 1)
    for i in range(tp_count1.size):
        l0, l1 = bins[i], bins[i + 1]
        mask = (delta >= l0) & (delta < l1)
        tp_count1[i] = np.sum(score_label1[mask] == "TP")
        fn_count1[i] = np.sum(score_label1[mask] == "FN")
        tp_count2[i] = np.sum(score_label2[mask] == "TP")
        fn_count2[i] = np.sum(score_label2[mask] == "FN")
    # inverse for unit_id2
    tp_count2 = tp_count2[::-1]
    fn_count2 = fn_count2[::-1]
    return tp_count1, fn_count1, tp_count2, fn_count2