code: public JmxMessage parameter(Object arg, Class<?> argType) {
          if (mbeanInvocation == null) {
              throw new CitrusRuntimeException("Invalid access to operation parameter for JMX message");
          }
  
          if (mbeanInvocation.getOperation() == null) {
              throw new CitrusRuntimeException("Invalid access to operation parameter before operation was set for JMX message");
          }
  
          if (mbeanInvocation.getOperation().getParameter() == null) {
              mbeanInvocation.getOperation().setParameter(new ManagedBeanInvocation.Parameter());
          }
  
          OperationParam operationParam = new OperationParam();
          operationParam.setValueObject(arg);
          operationParam.setType(argType.getName());
          mbeanInvocation.getOperation().getParameter().getParameter().add(operationParam);
          return this;
      }
docs: Adds operation parameter with custom parameter type.
  @param arg
  @param argType
  @return