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: test_gem_ext_ext_conf_builder.rb
    path of file: ./repos/ruby/test/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "helper"
require "rubygems/ext"

class TestGemExtExtConfBuilder < Gem::TestCase
  def setup
    
  def test_class_make_no_Makefile
    error = assert_raise Gem::InstallError do
      Gem::Ext::ExtConfBuilder.make @ext, ["output"], @ext
    end

    assert_equal "Makefile not found", error.message
  end