docs: public JmxMessage attribute(String name, Object value, Class<?> valueType) {
          if (mbeanInvocation == null) {
              throw new CitrusRuntimeException("Invalid access to attribute for JMX message");
          }
  
          ManagedBeanInvocation.Attribute attribute = new ManagedBeanInvocation.Attribute();
          attribute.setName(name);
          if (value != null) {
              attribute.setValueObject(value);
              attribute.setType(valueType.getName());
          }
  
          mbeanInvocation.setAttribute(attribute);
          return this;
      }