message: Fix DoExecution
diff: @@ -85,11 +85,13 @@ void World::DoExecution(const float& delta_time) {
  world_time_ += delta_time;
  // Execute motion
  for (auto agent : agents_) {
  + if (agent.second) {
  if (agent.second->GetBehaviorStatus() ==
  models::behavior::BehaviorStatus::VALID) {
  agent.second->Execute(world_time_);
  }
  }
  + }
  RemoveInvalidAgents();
  }
  