class Gem::Commands::UpdateCommand

def install_rubygems(version) # :nodoc:
  args = update_rubygems_arguments
  update_dir = File.join Gem.dir, 'gems', "rubygems-update-#{version}"
  Dir.chdir update_dir do
    say "Installing RubyGems #{version}" unless options[:silent]
    installed = preparing_gem_layout_for(version) do
      system Gem.ruby, '--disable-gems', 'setup.rb', *args
    end
    say "RubyGems system software updated" if installed unless options[:silent]
  end
end