code: def set_vapp_port_forwarding_rules(vappid, network_name, config={})
        builder = Nokogiri::XML::Builder.new do |xml|
        xml.NetworkConfigSection(
          "xmlns" => "http://www.vmware.com/vcloud/v1.5",
          "xmlns:ovf" => "http://schemas.dmtf.org/ovf/envelope/1") {
          xml['ovf'].Info "Network configuration"
          xml.NetworkConfig("networkName" => network_name) {
            xml.Configuration {
              xml.ParentNetwork("href" => "#{@api_url}/network/#{config[:parent_network]}")
              xml.FenceMode(config[:fence_mode] || 'isolated')
              xml.Features {
                xml.NatService {
                  xml.IsEnabled "true"
                  xml.NatType "portForwarding"
                  xml.Policy(config[:nat_policy_type] || "allowTraffic")
                  config[:nat_rules].each do |nat_rule|
                    xml.NatRule {
                      xml.VmRule {
                        xml.ExternalPort nat_rule[:nat_external_port]
                        xml.VAppScopedVmId nat_rule[:vm_scoped_local_id]
                        xml.VmNicId(nat_rule[:nat_vmnic_id] || "0")
                        xml.InternalPort nat_rule[:nat_internal_port]
                        xml.Protocol(nat_rule[:nat_protocol] || "TCP")
                      }
                    }
                  end
                }
              }
            }
          }
        }
        end
  
        params = {
          'method' => :put,
          'command' => "/vApp/vapp-#{vappid}/networkConfigSection"
        }
  
        response, headers = send_request(params, builder.to_xml, "application/vnd.vmware.vcloud.networkConfigSection+xml")
  
        task_id = headers[:location].gsub(/.*\/task\//, "")
        task_id
      end
docs: Set vApp port forwarding rules
  
   - vappid: id of the vapp to be modified
   - network_name: name of the vapp network to be modified
   - config: hash with network configuration specifications, must contain an array inside :nat_rules with the nat rules to be applied.