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: helper.rb
    path of file: ./repos/iruby/test/iruby/application
    
    the code of the file until where you have to start completion: require "helper"
require "open3"
require "rbconfig"

require "iruby/application"

module IRubyTest
  module ApplicationTests
    class ApplicationTestBase < TestBase
      DEFAULT_KERNEL_
    
      def ensure_iruby_kernel_is_installed(kernel_name=nil)
        if kernel_name
          system(*iruby_command("register", "--name=#{kernel_name}"), out: File::NULL, err: File::NULL)
        else
          system(*iruby_command("register"), out: File::NULL, err: File::NULL)
          kernel_name = DEFAULT_KERNEL_NAME
        end