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: drbtest.rb
    path of file: ./repos/artichoke/artichoke-backend/vendor/ruby/test/drb
    
    the code of the file until where you have to start completion: # frozen_string_literal: false
require 'test/unit'
require 'envutil'
require 'drb/drb'
require 'drb/extservm'
require 'timeout'

module DRbTests

class DRbService
  @@ruby = [EnvUtil.rubybin]
  @@ruby << "-d" if $DEBUG
  def self.add_service_command(nm)
    dir = File.dirname(File.expand_path(__FILE__))
    DRb::ExtServManager.command[nm] = @@ruby + ["#{dir}/#{nm}"]
  end

  
    
  def test_02_unknown
    obj = @there.unknown_class
    assert_kind_of(DRb::DRbUnknown, obj)
    assert_equal('DRbTests::Unknown2', obj.name)

    obj = @there.unknown_module
    assert_kind_of(DRb::DRbUnknown, obj)
    assert_equal('DRbTests::DRbEx::', obj.name)

    assert_raise(DRb::DRbUnknownError) do
      @there.unknown_error
    end

    onecky = FailOnecky.new('3')

    assert_raise(FailOnecky::OneckyError) do
      @there.sample(onecky, 1, 2)
    end
  end