The recipe allows to be constructed using a provided ScheduledExecutorService or using an internally created Executor. The code tries to be generic and when closing the recipe is only cancelling recipe touch task, BUT the Executor is never shutdown. That means that when the Executor is internally created, the Executor Thread will remain there forever.

The recipe MUST distinguish both cases, and when the Executor is internally created is MUST be shutdown when recipe is closed. When the Executor is externally provided the recipe will document that it will not shutdown when closing and it is up to the recipe user to properly shutdown the Executor