Is there some way to test a Grails CXF client call by providing a response?

I have a grails 2.3.x webapp that uses CXF to call to backend SOAP services. I'd like to set up a test where I call my service, but provide the response back from the service as a string directly to test it.

So, I want to set up a test that will autowire the service. I then set the response somehow as a string. Call the service method under test and under the covers it receives the response string I set and the request is ignored (or possibly even could check its validity). It parses the response which goes through the service code and returns as usual.

I don't want to have to run a separate server for the test. Is there someway to put in the response directly?