docs: public void marshall(DirectConnectGatewayAttachment directConnectGatewayAttachment, ProtocolMarshaller protocolMarshaller) {
  
          if (directConnectGatewayAttachment == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(directConnectGatewayAttachment.getDirectConnectGatewayId(), DIRECTCONNECTGATEWAYID_BINDING);
              protocolMarshaller.marshall(directConnectGatewayAttachment.getVirtualInterfaceId(), VIRTUALINTERFACEID_BINDING);
              protocolMarshaller.marshall(directConnectGatewayAttachment.getVirtualInterfaceRegion(), VIRTUALINTERFACEREGION_BINDING);
              protocolMarshaller.marshall(directConnectGatewayAttachment.getVirtualInterfaceOwnerAccount(), VIRTUALINTERFACEOWNERACCOUNT_BINDING);
              protocolMarshaller.marshall(directConnectGatewayAttachment.getAttachmentState(), ATTACHMENTSTATE_BINDING);
              protocolMarshaller.marshall(directConnectGatewayAttachment.getStateChangeError(), STATECHANGEERROR_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }