def available_backends(self, filters=None):
    backends = self.backends
    filters = (filters or {})
    for (key, value) in filters.items():
        backends = {name: instance for (name, instance) in backends.items() if (instance.configuration.get(key) == value)}
    return list(backends.values())
def available_backends(self, filters=None):
    backends = self.backends
    filters = (filters or {})
    for (key, value) in filters.items():
        backends = {name: instance for (name, instance) in backends.items() if (instance.configuration.get(key) == value)}
    return list(backends.values())