plchangesposid <int> -> fetch_changes
prio <int> <int>|<range> -> self._fetch_nothing,
prioid <int> <int> -> self._fetch_nothing,
+rangeid <int> <range> -> self._fetch_nothing,
shuffle [<range>] -> fetch_nothing
swap <int> <int> -> fetch_nothing
swapid <int> <int> -> fetch_nothing