def current_sync_for_user(self, sync_config, since_token=None,
                              full_state=False):
        if since_token is None or full_state:
            return self.full_state_sync(sync_config, since_token)
        else:
            return self.incremental_sync_with_gap(sync_config, since_token)
Get the sync for client needed to match what the server has now.
dataset/ETHPy150Open matrix-org/synapse/synapse/handlers/sync.py/SyncHandler.current_sync_for_user