code: def poweroff_vapp(vAppId)
        builder = Nokogiri::XML::Builder.new do |xml|
        xml.UndeployVAppParams(
          "xmlns" => "http://www.vmware.com/vcloud/v1.5") {
          xml.UndeployPowerAction 'powerOff'
        }
        end
  
        params = {
          'method' => :post,
          'command' => "/vApp/vapp-#{vAppId}/action/undeploy"
        }
  
        response, headers = send_request(params, builder.to_xml,
                        "application/vnd.vmware.vcloud.undeployVAppParams+xml")
        task_id = headers[:location].gsub(/.*\/task\//, "")
        task_id
      end
docs: Shutdown a given vapp