You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: set_cache.rb
    path of file: ./repos/gitlabhq/lib/gitlab
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# Interface to the Redis-backed cache store to keep track of complete cache keys
# for a ReactiveCache resource.
module Gitlab
  class SetCache
    attr_reader :expires_in

    def initialize(expires_in: 2.weeks)
      @expires_in = expires_in
    end

    def cache_key(key)
      "#{cache_namespace}:#{key}:set"
    end

    # Retur
    
    def expire(*keys)
      return 0 if keys.empty?

      with do |redis|
        keys_to_expire = keys.map { |key| cache_key(key) }

        Gitlab::Instrumentation::RedisClusterValidator.allow_cross_slot_commands do
          if Gitlab::Redis::ClusterUtil.cluster?(redis)
            Gitlab::Redis::ClusterUtil.batch_unlink(keys_to_expire, redis)
          else
            redis.unlink(*keys_to_expire)
          end
        end
      end