docs: def docker_fabric(*args, **kwargs):
      """
      :param args: Positional arguments to Docker client.
      :param kwargs: Keyword arguments to Docker client.
      :return: Docker client.
      :rtype: dockerfabric.apiclient.DockerFabricClient | dockerfabric.cli.DockerCliClient
      """
      ci = kwargs.get('client_implementation') or env.get('docker_fabric_implementation') or CLIENT_API
      if ci == CLIENT_API:
          return docker_api(*args, **kwargs)
      elif ci == CLIENT_CLI:
          return docker_cli(*args, **kwargs)
      raise ValueError("Invalid client implementation.", ci)