peek_timestamp(const smartlist_t *timestamps_u64_usecs)
{
  uint64_t *timestamp_ptr = smartlist_get(timestamps_u64_usecs, 0);

  if (BUG(!timestamp_ptr)) {
    log_err(LD_CIRC, "Congestion control timestamp list became empty!");
    return 0;
  }

  return *timestamp_ptr;
}
peek_timestamp(const smartlist_t *timestamps_u64_usecs)
{
  uint64_t *timestamp_ptr = smartlist_get(timestamps_u64_usecs, 0);

  if (BUG(!timestamp_ptr)) {
    log_err(LD_CIRC, "Congestion control timestamp list became empty!");
    return 0;
  }

  return *timestamp_ptr;
}