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: reaper.rb
    path of file: ./repos/ArchiveBot/cogs
    
    the code of the file until where you have to start completion: require 'celluloid'
require 'redis'

require File.expand_path('../../lib/job', __FILE__)

##
# Watches jobs for signs of heart failure, and kills the jobs once they've been
# without a heartbeat for too long.
#
# Theory of operation
# -------------------
#
# For each active job, a Reaper periodically:
#
# 1. Chec
    
  def check_one(ident)
    data = @redis.hmget(ident, LAH, HB)
    old = data[0]
    new = data[1]

    # We can't reap the undead: if there's no heartbeat for the job, just skip
    # it.
    return if new.nil?

    # If no heartbeat has yet been acknowledged, acknowledge the current
    # heartbeat and return.
    if old.nil?
      @redis.hset(ident, LAH, new)
      return
    end