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: liveness_listener.rb
    path of file: ./repos/karafka/lib/karafka/swarm
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Karafka
  module Swarm
    # Simple listener for swarm n
    
      def periodically
        return if monotonic_now - @last_checked_at < liveness_interval

        synchronize do
          @last_checked_at = monotonic_now

          yield
        end
      end