code: def _prepare_route(self, attrs):
          
          if type(attrs) not in (list, tuple):
              LOGGER.error('Invalid route, must be a list or tuple: %r', attrs)
              return
  
          # By default there are not any extra kwargs
          kwargs = None
  
          # If there is a regex based route, set it up with a raw string
          if attrs[0] == 're':
              route = r'%s' % attrs[1]
              classpath = attrs[2]
              if len(attrs) == 4:
                  kwargs = attrs[3]
          else:
              route = r'%s' % attrs[0]
              classpath = attrs[1]
              if len(attrs) == 3:
                  kwargs = attrs[2]
  
          LOGGER.debug('Initializing route: %s with %s', route, classpath)
          try:
              handler = self._import_class(classpath)
          except ImportError as error:
              LOGGER.error('Class import error for %s: %r', classpath, error)
              return None
  
          # Setup the prepared route, adding kwargs if there are any
          prepared_route = [route, handler]
          if kwargs:
              prepared_route.append(kwargs)
  
          # Return the prepared route as a tuple
          return tuple(prepared_route)
docs: Take a given inbound list for a route and parse it creating the
          route and importing the class it belongs to.
  
          :param list attrs: Route attributes
          :rtype: list