TestFor documentation

[fiallega]

I am not sure how to find the documentation on how to use the TestFor annotation.
For example, when using TestFor with a service like
@TestFor(MyService), I was able to find out that the variable that is created is 'service' through an example in a post, but  I could not derive that from anywhere else.
I looked into
http://grails.org/doc/1.4.x/api/index.html?grails/test/mixin/services/ServiceUnitTestMixin.html
and in
http://grails.org/doc/1.4.x/api/grails/test/mixin/TestFor.html

My general problem right now is that although by reading the  SpringSource Blog article and documentation I find the new testing framework very powerful, I have no idea how to find out the details I run into.