Figure out the weirdness with adaption relating to SecureAccessTokenAuthorizerStorageServer

_storage_server.py ends with

# I don't understand why this is required.                                                                                                                                                                                                                                     
# SecureAccessTokenAuthorizerStorageServer is-a Referenceable.  It seems like                                                                                                                                                                                                  
# the built in adapter should take care of this case.                                                                                                                                                                                                                          
from twisted.python.components import (
    registerAdapter,
)
from foolscap.referenceable import (
    ReferenceableSlicer,
)
from foolscap.ipb import (
    ISlicer,
)
registerAdapter(ReferenceableSlicer, SecureAccessTokenAuthorizerStorageServer, ISlicer)

As the comment says, it's not clear to me why this is necessary. Figure it out and fix whatever the issue is so this code can go away or explain why it needs to remain.