code: def get_docker_tag(platform: str, registry: str) -> str:
      
      platform = platform if any(x in platform for x in ['build.', 'publish.']) else 'build.{}'.format(platform)
      if not registry:
          registry = "mxnet_local"
      return "{0}/{1}".format(registry, platform)
docs: :return: docker tag to be used for the container