code: def _parse_exchange_token_response(content):
      
      resp = {}
      content = _helpers._from_bytes(content)
      try:
          resp = json.loads(content)
      except Exception:
          # different JSON libs raise different exceptions,
          # so we just do a catch-all here
          resp = _helpers.parse_unique_urlencoded(content)
  
      # some providers respond with 'expires', others with 'expires_in'
      if resp and 'expires' in resp:
          resp['expires_in'] = resp.pop('expires')
  
      return resp
docs: Parses response of an exchange token request.
  
      Most providers return JSON but some (e.g. Facebook) return a
      url-encoded string.
  
      Args:
          content: The body of a response
  
      Returns:
          Content as a dictionary object. Note that the dict could be empty,
          i.e. {}. That basically indicates a failure.