That is the default code for a newly created Java Action. It will throw an exception saying the action has not been implemented.
To fix this, go into your javasource folder, and find your Wait.java source. You can then edit this to remove the throw, and add the functionality you require.
If you are trying to write custom code to add a delay, you may instead want to use the Delay action in the Community Commons module available in the Marketplace.
I hope this helps.