class Bundler::Runtime

def cache(custom_path = nil)
  cache_path = cache_path(custom_path)
  FileUtils.mkdir_p(cache_path) unless File.exist?(cache_path)
  Bundler.ui.info "Updating files in vendor/cache"
  specs.each do |spec|
    next if spec.name == 'bundler'
    spec.source.cache(spec, custom_path) if spec.source.respond_to?(:cache)
  end
  Dir[cache_path.join("*/.git")].each do |git_dir|
    FileUtils.rm_rf(git_dir)
    FileUtils.touch(File.expand_path("../.bundlecache", git_dir))
  end
  prune_cache(custom_path) unless Bundler.settings[:no_prune]
end