Unlike the previous two examples, this algorithm queues up all of the cells in Redis’s List data structure. It then uses the UniformRateLimiter class to determine when to pop a cell from the List.

In contrast, a data structure is a concrete implementation of one or more ADTs, similar to how Java classes implement interfaces. Examples of ADTs include Employee, Vehicle, Array, and List.

Thus, if you create list data structures that are highly recursive and have many cycles, you should be careful about saving your lists. For example, suppose list A contains list B. When you save list ...