code: def delete_all(self, filter=None, timeout=-1):
          
          return self._client.delete_all(filter=filter, timeout=timeout)
docs: Delete an SNMPv3 User based on User name specified in filter. The user will be deleted only if it has no associated destinations.
  
          Args:
              username: ID or URI of SNMPv3 user.
              filter: A general filter/query string to narrow the list of items returned.
                      The default is no filter - all resources are returned.
  
          Returns:
              bool: Indicates if the resource was successfully deleted.