private void unregisterUndeployedFunctions(List<Function<?>> previouslyRegisteredFunctions,
      List<Function<?>> registeredFunctions) {

    if (previouslyRegisteredFunctions == null) {
      return;
    }

    List<String> currentlyRegisteredFunctionIDs =
        registeredFunctions.stream().map(Function::getId).collect(Collectors.toList());
    previouslyRegisteredFunctions.stream().map(Function::getId)
        .filter(functionId -> !currentlyRegisteredFunctionIDs.contains(functionId))
        .forEach(FunctionService::unregisterFunction);
  }
Scan the JAR file and attempt to register any function classes found.

@param jarFile The {@link File} that contains {@link Function} that are to be registered
geode-core/src/main/java/org/apache/geode/cache/internal/execute/FunctionToFileTracker.java