def __init__(self, default=None, **kwargs):
    # TODO: enforce the type of variants using the Addressable framework.
    super(Variants, self).__init__(default=default, **kwargs)
Return a fully qualified resource name for Cloud Pub/Sub.
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/engine/exp/struct.py/Variants.__init__--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/cloud-pubsub-samples-python/cmdline-pull/pubsub_sample.py/fqrn