ExclusiveEntityTransaction A transaction object that provides an functions for making structural changes.
Begins an exclusive entity transaction, which allows you to make structural changes inside a Job.
ExclusiveEntityTransaction allows you to create and destroy entities from a job. The purpose is
to enable procedural generation scenarios where instantiation on big scale must happen on jobs. As the
name implies it is exclusive to any other access to the EntityManager.
An exclusive entity transaction should be used on a manually created EntityManager.World that acts as a
staging area to construct and setup entities.
After the job has completed you can end the transaction and use
EntityManager.MoveEntitiesFrom to move the entities to an active EntityManager.World.