How to use the gfootball.env.wrappers.Simple115StateWrapper function in gfootball

Args:
    env: A GFootball gym environment.
    representation: See create_environment.representation comment.
    channel_dimensions: (width, height) tuple that represents the dimensions of
       SMM or pixels representation.
  Returns:
    Google Research Football environment.
  """
  if representation.startswith('pixels'):
    env = wrappers.PixelsStateWrapper(env, 'gray' in representation,
                                      channel_dimensions)
  elif representation == 'simple115':
    env = wrappers.Simple115StateWrapper(env)
  elif representation == 'simple115v2':
    env = wrappers.Simple115StateWrapper(env, True)
  elif representation == 'extracted':
    env = wrappers.SMMWrapper(env, channel_dimensions)
  elif representation == 'raw':
    pass
  else:
    raise ValueError('Unsupported representation: {}'.format(representation))
  return env

def _process_representation_wrappers(env, representation, channel_dimensions):
  """Wraps with necessary representation wrappers.

  Args:
    env: A GFootball gym environment.
    representation: See create_environment.representation comment.
    channel_dimensions: (width, height) tuple that represents the dimensions of
       SMM or pixels representation.
  Returns:
    Google Research Football environment.
  """
  if representation.startswith('pixels'):
    env = wrappers.PixelsStateWrapper(env, 'gray' in representation,
                                      channel_dimensions)
  elif representation == 'simple115':
    env = wrappers.Simple115StateWrapper(env)
  elif representation == 'simple115v2':
    env = wrappers.Simple115StateWrapper(env, True)
  elif representation == 'extracted':
    env = wrappers.SMMWrapper(env, channel_dimensions)
  elif representation == 'raw':
    pass
  else:
    raise ValueError('Unsupported representation: {}'.format(representation))
  return env

def observation(self, observation):
    """Converts an observation into simple115 (or simple115v2) format."""
    return Simple115StateWrapper.convert_observation(observation, self._fixed_positions)