    # File lib/chef/knife/cookbook_download.rb, line 104
          def available_versions
            @available_versions ||= begin
              versions = Chef::CookbookVersion.available_versions(@cookbook_name).map do |version|
                Chef::Version.new(version)
              end
              versions.sort!
              versions
            end
            #pp :available_versions => @available_versions
            @available_versions
          end