available_set_for

# File lib/rubygems/dependency_installer.rb, line 171
  def available_set_for dep_or_name, version # :nodoc:
    if String === dep_or_name then
      find_spec_by_name_and_version dep_or_name, version, @prerelease
    else
      dep = dep_or_name.dup
      dep.prerelease = @prerelease
      @available = find_gems_with_sources dep
    end

    @available.pick_best!
  end