def total_pages(key, page_size)
      (Amico.redis.zcard(key) / page_size.to_f).ceil
    end
def total_pages(key, page_size)
      (Amico.redis.zcard(key) / page_size.to_f).ceil
    end
Count the total number of pages for a given key in a Redis sorted set.

 @param key [String] Redis key.
 @param page_size [int] Page size from which to calculate total pages.

 @return total number of pages for a given key in a Redis sorted set.