code: function onList(newList) {
  		var current = this.currentList || [];
  		newList = newList || [];
  		if (current[offPatchesSymbol]) {
  			current[offPatchesSymbol](this.onPatchesNotify, "notify");
  		}
  		var patches = diff(current, newList);
  		this.currentList = newList;
  		this.onPatchesNotify(patches);
  		if (newList[onPatchesSymbol]) {
  			// If observable, set up bindings on list changes
  			newList[onPatchesSymbol](this.onPatchesNotify, "notify");
  		}
  	}
docs: when the list changes, teardown the old list bindings and setup the new list