How to use the fire.trace function in fire

Args:
      code: The status code that the FireExit should contain.
      regexp: stdout must match this regex.
    Yields:
      Yields to the wrapped context.
    """
    with self.assertOutputMatches(stderr=regexp):
      with self.assertRaises(core.FireExit):
        try:
          yield
        except core.FireExit as exc:
          if exc.code != code:
            raise AssertionError('Incorrect exit code: %r != %r' % (exc.code,
                                                                    code))
          self.assertIsInstance(exc.trace, trace.FireTrace)
          raise

ValueError: If there are arguments that cannot be consumed.
    ValueError: If --completion is specified but no name available.
  """
  verbose = parsed_flag_args.verbose
  interactive = parsed_flag_args.interactive
  separator = parsed_flag_args.separator
  show_completion = parsed_flag_args.completion
  show_help = parsed_flag_args.help
  show_trace = parsed_flag_args.trace

  # component can be a module, class, routine, object, etc.
  if component is None:
    component = context

  initial_component = component
  component_trace = trace.FireTrace(
      initial_component=initial_component, name=name, separator=separator,
      verbose=verbose, show_help=show_help, show_trace=show_trace)

  instance = None
  remaining_args = args
  while True:
    last_component = component
    initial_args = remaining_args

    if not remaining_args and (show_help or interactive or show_trace
                               or show_completion is not None):
      # Don't initialize the final class or call the final function unless
      # there's a separator after it, and instead process the current component.
      break

    if _IsHelpShortcut(component_trace, remaining_args):

component: The object that is the result of the callable call.
    remaining_args: The remaining args that haven't been consumed yet.
  """
  if not target:
    target = component
  filename, lineno = inspectutils.GetFileAndLine(component)
  metadata = decorators.GetMetadata(component)
  fn = component.__call__ if treatment == 'callable' else component
  parse = _MakeParseFn(fn, metadata)
  (varargs, kwargs), consumed_args, remaining_args, capacity = parse(args)
  component = fn(*varargs, **kwargs)

  if treatment == 'class':
    action = trace.INSTANTIATED_CLASS
  elif treatment == 'routine':
    action = trace.CALLED_ROUTINE
  else:
    action = trace.CALLED_CALLABLE
  component_trace.AddCalledComponent(
      component, target, consumed_args, filename, lineno, capacity,
      action=action)

  return component, remaining_args

the component itself will be used as target.
  Returns:
    component: The object that is the result of the callable call.
    remaining_args: The remaining args that haven't been consumed yet.
  """
  if not target:
    target = component
  filename, lineno = inspectutils.GetFileAndLine(component)
  metadata = decorators.GetMetadata(component)
  fn = component.__call__ if treatment == 'callable' else component
  parse = _MakeParseFn(fn, metadata)
  (varargs, kwargs), consumed_args, remaining_args, capacity = parse(args)
  component = fn(*varargs, **kwargs)

  if treatment == 'class':
    action = trace.INSTANTIATED_CLASS
  elif treatment == 'routine':
    action = trace.CALLED_ROUTINE
  else:
    action = trace.CALLED_CALLABLE
  component_trace.AddCalledComponent(
      component, target, consumed_args, filename, lineno, capacity,
      action=action)

  return component, remaining_args

"""
  if not target:
    target = component
  filename, lineno = inspectutils.GetFileAndLine(component)
  metadata = decorators.GetMetadata(component)
  fn = component.__call__ if treatment == 'callable' else component
  parse = _MakeParseFn(fn, metadata)
  (varargs, kwargs), consumed_args, remaining_args, capacity = parse(args)
  component = fn(*varargs, **kwargs)

  if treatment == 'class':
    action = trace.INSTANTIATED_CLASS
  elif treatment == 'routine':
    action = trace.CALLED_ROUTINE
  else:
    action = trace.CALLED_CALLABLE
  component_trace.AddCalledComponent(
      component, target, consumed_args, filename, lineno, capacity,
      action=action)

  return component, remaining_args