Is it mandatory to use start() and stop() methods while implementing JBoss MBean service?

I am trying to learn JMX provided by JBoss with this example: ExampleHelloWorldService

After deploying the SAR file, I am able to see the operation and attributes in JConsole.

In the example, start() and stop() methods are used in the MBean implementation class as a purpose of service lifecycle callback.

Is it really necessary, to include these methods? I tried by removing these methods and I didn't see any difference in the result i.e. I am still able to access both the attribute and operation in the JConsole.