Elliotte Rusty Harold opened MPIR-472 and commented
This class does more work in its constrcutor than is safe for a constructor to do, and can leave objects in unexpected and not fully initialized states. It can also throw unexpected, undocumented, and uncaught RuntimeExceptions. Consider converting in part to a factory method that can throw context appropriate exceptions or otherwise preventing objects in bad states.
No further details from MPIR-472