Rank-based Cache with Concurrency

You need to design a Rank-based Cache module where the rank of cache entries can change dynamically. Consider the following questions: How would you handle concurrency issues in a multi-threaded environment? Specify where locks are needed in the code. How would you handle if the rank from the data source changes rapidly? If the rank is based on the last access time of the entry, how would you implement this? Provide code examples and test cases. Example Input 1 put user1 data1 1 get user1 put user2 data2 2 update_ranks