(self)
return -1
Returns the last modified time of the index, or -1 if the backend
        doesn't support last-modified times.
Returns the last modified time of the index, or -1 if the backend
        doesn't support last-modified times.
Returns the last modified time of the index or - 1 if the backend doesn t support last - modified times .
def last_modified(self):
        """Returns the last modified time of the index, or -1 if the backend
        doesn't support last-modified times.
        """
        return -1
def last_modified ( self ) : return - 1