def METHOD_NAME(benchmark_spec):
  """Stop and remove docker containers. Remove images.
  Args:
    benchmark_spec: The benchmark specification. Contains all data that is
        required to run the benchmark.
  """
  server_seed = benchmark_spec.vm_groups['server_seed'][0]
  servers = benchmark_spec.vm_groups['servers']
  def CleanupServerCommon(vm):
    vm.RemoteCommand('sudo docker rm cassandra-server')
  def CleanupServerSeed(vm):
    vm.RemoteCommand('sudo docker stop cassandra-server-seed')
    CleanupServerCommon(vm)
  def CleanupServer(vm):
    vm.RemoteCommand('sudo docker stop cassandra-server')
    CleanupServerCommon(vm)
  target_arg_tuples = ([(CleanupServerSeed, [server_seed], {})] +
                       [(CleanupServer, [vm], {}) for vm in servers])
  background_tasks.RunParallelThreads(target_arg_tuples, len(target_arg_tuples))