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: agent_check_job.rb
    path of file: ./repos/huginn/app/jobs
    
    the code of the file until where you have to start completion: class AgentCheckJob < Ac
    
  def perform(agent_id)
    agent = Agent.find(agent_id)
    begin
      return if agent.unavailable?
      agent.check
      agent.last_check_at = Time.now
      agent.save!
    rescue => e
      agent.error "Exception during check. #{e.message}: #{e.backtrace.join("\n")}"
      raise
    end