NewBlockRepository returns a new instance of the BlockRepository with the specified Redis client and expiration time.

NewSubscriberRepository is a constructor for SubscriberRepository that takes in a Redis client instance and an expiration time for data stored in the Redis cache, and returns a pointer to a SubscriberRepository instance.

BlockRepository is a structure that holds information about the current block.

SubscriberRepository is a struct that represents a repository for subscriber data.