List<LocationMemento> getNextLocations() {
			List<LocationMemento> nextLocations = new ArrayList<>();
			for (int i = currentLocation + 1; i < list.size(); i++) {
				nextLocations.add(list.get(i));
			}
			return nextLocations;
		}
Find the previous history LocationMemento that contains a different function. If no such
LocationMemento is found, null is returned.

@param navigatable the navigatable being navigated
@param moveTo true means after finding, get current location to it. false to just find
           and do nothing
@return previous LocationMemento, or null if no previous function found
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/navigation/NavigationHistoryPlugin.java