static gboolean compare_by_guid(gconstpointer guid_a, gconstpointer guid_b) {
  return memcmp(guid_a, guid_b, sizeof(endpoint_guid)) == 0;
}
static gboolean compare_by_guid(gconstpointer guid_a, gconstpointer guid_b) {
  return memcmp(guid_a, guid_b, sizeof(endpoint_guid)) == 0;
}