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: homebrew_update.rb
    path of file: ./repos/chef/lib/chef/resource
    
    the code of the file until where you have to start completion: #
# Author:: Joshua Timberman (<jtimberman@chef.io>)
# Author:: Dan Webb (<dan@webb-agile-solutions.ltd>)
#
# Copyright:: Copyright (c) Chef Software Inc.
# Copyright:: Copyright (c) Webb Agile Solutions Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");

    
        def do_update
          directory BREW_STAMP_DIR do
            recursive true
          end

          file BREW_STAMP do
            content "BREW::Update::Post-Invoke-Success\n"
            action :create_if_missing
          end

          execute "brew update" do
            command %w{brew update}
            default_env true
            user find_homebrew_uid
            notifies :touch, "file[#{BREW_STAMP}]", :immediately
          end
        end