config.vm.box = windows_2012r2_box
        windows_common config, box
      end
    end
  end

  windows_2016_box = ENV['VAGRANT_WINDOWS_2016_BOX']
  if windows_2016_box && windows_2016_box.empty? == false
    'windows-2016'.tap do |box|
      config.vm.define box, define_opts do |config|
        config.vm.box = windows_2016_box
        windows_common config, box
      end
    end
  end
end