Why am I getting an `unknown registry` error? How can I start and then find a Registry in my application supervision tree?

Also, I can’t figure out how to just print out all the keys in the Registry. The keys method requires a pid to be passed in and it only returns keys registered by that pid. I just want to see the keys to all processes that any process may have registered.

# from some other process at a later time that only wants to lookup pid, never register them...
Registry.keys(MyAppProcessRegistry, some_pid) # <-- but I don't know the pid

Why do I have to pass in some_pid??? – shouldn’t I be getting values based on keys, not getting keys based on values?

Shouldn’t Registry.keys only take a single argument – the registry name. I just want a list of all the keys in the registry. Why does it take two arguments?