void ArangoScheduler::makePersistent (const mesos::Offer& offer,
                                      const mesos::Resources& resources) const {
  mesos::Offer::Operation reserve;
  reserve.set_type(mesos::Offer::Operation::CREATE);
  reserve.mutable_create()->mutable_volumes()->CopyFrom(resources);

  _driver->acceptOffers({offer.id()}, {reserve});
}
void ArangoScheduler::reserveDynamically (const mesos::Offer& offer,
                                          const mesos::Resources& resources) const {
  mesos::Offer::Operation reserve;
  reserve.set_type(mesos::Offer::Operation::RESERVE);
  reserve.mutable_reserve()->mutable_resources()->CopyFrom(resources);

  _driver->acceptOffers({offer.id()}, {reserve});
}