Extract the entity id from an incoming message. If is returned the message will be `unhandled`, i.e. posted as `Unhandled` messages on the event stream

Extract the message to send to the entity from an incoming message. Note that the extracted message does not have to be the same as the incoming message to support wrapping in message envelope that is unwrapped before sending to the entity actor.

Extract the entity id from an incoming message. Only messages that passed the EntityId(Object) method will be used as input to this method.