def removeAssociation(self, server_url, handle):
   """
   This method removes the matching association if it's found, and returns
   whether the association was removed or not.
   """
   query = Association.gql('WHERE url = :1 AND handle = :2',
                           server_url, handle)
   return self._delete_first(query)
  def cleanupAssociations(self):
    """Remove expired associations from the store.

    This method is not called in the normal operation of the
    library.  It provides a way for store admins to keep
    their storage from filling up with expired data.

    @return: the number of associations expired.
    @returntype: int
    """
    query = Association.gql('WHERE created < :1', self._expiration_datetime())
    return self._cleanup_batch(query)