'Return the storage backend, setting its loaded data to the ``data``
argument.
This method avoids the storage ``_get`` method from getting called so
that other parts of the storage backend can be tested independent of
the message retrieval logic.'

def get_storage(self, data=None):

    storage = self.storage_class(self.get_request())
    storage._loaded_data = (data or [])
    return storage
