Other thoughts:
1. in tearDown, we should also do `Entities.destroyAll(origManagementContext)` - see RebindEntityTest.tearDown
2. keep the test entity simple; start will check if it's a machineProvisioning location and if so call `loc.obtain()`; stop will call `loc.release(machine)` if it previously called obtain. Be a bit careful with ensuring the machine really is released, but don't worry about complexity of tasks in SoftwareProcess.
3. record the machine that was created before calling `rebind()`. so that tearDown can make sure the machine really is terminated (that would need to use the original location before doing `Entities.destroy(origManagementContext)`).