def util_setup_fake_fetcher(prerelease = false)
    require 'zlib'
    require 'socket'
    require 'rubygems/remote_fetcher'

    @fetcher = Gem::FakeFetcher.new

    util_make_gems(prerelease)
    Gem::Specification.reset

    @all_gems = [@a1, @a2, @a3a, @a_evil9, @b2, @c1_2].sort
    @all_gem_names = @all_gems.map { |gem| gem.full_name }

    gem_names = [@a1.full_name, @a2.full_name, @a3a.full_name, @b2.full_name]
    @gem_names = gem_names.sort.join("\n")

    Gem::RemoteFetcher.fetcher = @fetcher
  end
#
Sets up a fake fetcher using the gems from #util_make_gems.  Optionally
additional +prerelease+ gems may be included.

Gems created by this method may be fetched using Gem::RemoteFetcher.