code: def diff_config(ctx, second_host, mode):
      
      mp_pool = multiprocessing.Pool(multiprocessing.cpu_count() * 2)
      for ip in ctx.obj['hosts']:
          mp_pool.apply_async(wrap.open_connection, args=(ip,
                              ctx.obj['conn']['username'],
                              ctx.obj['conn']['password'],
                              wrap.diff_config, [second_host, mode],
                              ctx.obj['out'],
                              ctx.obj['conn']['connect_timeout'],
                              ctx.obj['conn']['session_timeout'],
                              ctx.obj['conn']['port']), callback=write_out)
      mp_pool.close()
      mp_pool.join()
docs: Config comparison between two devices.
  
      @param ctx: The click context paramter, for receiving the object dictionary
                | being manipulated by other previous functions. Needed by any
                | function with the @click.pass_context decorator.
      @type ctx: click.Context
      @param second_host: The IP/hostname of the second device to pull from
      @type second_host: str
      @param mode: The mode in which we are retrieving the config ('set' or
                 | 'stanza')
      @type mode: str
  
      @returns: None. Functions part of click relating to the command group
              | 'main' do not return anything. Click handles passing context
              | between the functions and maintaing command order and chaining.