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: handlers_test.rb
    path of file: ./repos/serviceworker-rails/test/serviceworker
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "test_helper"

class ServiceWorker::Handle
    
  def test_build_webpacker_handler
    return true unless defined?(::Webpacker)

    handler = ServiceWorker::Handlers.build(:webpacker)

    assert handler.is_a?(ServiceWorker::Handlers::WebpackerHandler)
  end