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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def list():
 """Print a listing of known running TensorBoard instances. TensorBoard instances that were killed uncleanly (e.g., with SIGKILL or SIGQUIT) may appear in this list even if they are no longer running. Conversely, this list may be missing some entries if your operating system's temporary directory has been cleared since a still-running TensorBoard instance started. """

  infos = manager.get_all()
  if not infos:
    print("No known TensorBoard instances running.")
    return

  print("Known TensorBoard instances:")
  for info in infos:
    template = "  - port {port}: {data_source} (started {delta} ago; pid {pid})"
    print(template.format(
        port=info.port,
        data_source=manager.data_source_from_info(info),
        delta=_time_delta_from_info(info),
        pid=info.pid,
    ))