'Modifies a SnapMirror relationship.'

def modify_snapmirror(self, source_vserver, source_volume, destination_vserver, destination_volume, schedule=None, policy=None, tries=None, max_transfer_rate=None):

    self._ensure_snapmirror_v2()
    api_args = {'source-volume': source_volume, 'source-vserver': source_vserver, 'destination-volume': destination_volume, 'destination-vserver': destination_vserver}
    if schedule:
        api_args['schedule'] = schedule
    if policy:
        api_args['policy'] = policy
    if (tries is not None):
        api_args['tries'] = tries
    if (max_transfer_rate is not None):
        api_args['max-transfer-rate'] = max_transfer_rate
    self.send_request('snapmirror-modify', api_args)
