How to set SOAP Action using JAXWS dispatch client API?

[Isuru Suriarachchi]

Hi all,

I'm using a JAXWS dispatch client (without generating proxy code) to invoke
a simple service. Now I want to engage addressing to this client and test
some asynchronous scenarios. But I can't find how to set the SOAP Action
through this dispatch client API. Can someone who's familiar with our JAXWS
client API tell me how to do this?

Thanks in advance,
~Isuru