docs: def authenticate_http_request(token=None):
      """Validate auth0 tokens passed in the request's header, hence ensuring
      that the user is authenticated. Code copied from:
      https://github.com/auth0/auth0-python/tree/master/examples/flask-api
  
      Return a PntCommonException if failed to validate authentication.
      Otherwise, return the token's payload (Also stored in stack.top.current_user)
      """
  
      if token:
          auth = token
      else:
          auth = request.headers.get('Authorization', None)
  
      if not auth:
          auth = request.cookies.get('token', None)
          if auth:
              auth = unquote_plus(auth)
  
      log.debug("Validating Auth header [%s]" % auth)
  
      if not auth:
          raise AuthMissingHeaderError('There is no Authorization header in the HTTP request')
  
      parts = auth.split()
  
      if parts[0].lower() != 'bearer':
          raise AuthInvalidTokenError('Authorization header must start with Bearer')
      elif len(parts) == 1:
          raise AuthInvalidTokenError('Token not found in Authorization header')
      elif len(parts) > 2:
          raise AuthInvalidTokenError('Authorization header must be Bearer + \s + token')
  
      token = parts[1]
  
      return load_auth_token(token)