Users should normally not use this class, but it is public case
for power users in case of integration with Cluster Sharding
entities that are not implemented with PersistentEntity.
This member is added by an implicit conversion from CommandEnvelope to
any2stringadd[CommandEnvelope] performed by method any2stringadd in scala.Predef.
Commands to PersistentEntity are wrapped in this envelope when sent via PersistentEntityRef (i.e. Cluster Sharding).
Users should normally not use this class, but it is public case for power users in case of integration with Cluster Sharding entities that are not implemented with PersistentEntity.