'Save a json value to the persistent storage on the backend.
The storage backend provides a small amount of persistent storage
that we can utilize for storing driver information.
:param key: The key utilized for storing/retrieving the data
:param store_data: a python data structure that will be stored as a
json value'

def save_backend_store(self, key, store_data):

    path = self.RESOURCE_PATHS.get('persistent-stores')
    store_data = json.dumps(store_data, separators=(',', ':'))
    data = {'key': key, 'value': store_data}
    self._invoke('POST', path, data)
