How to read a test-only file in Android unit test

For my Android app I'm writing unit tests that require reading some files. Since those are test-only files I don't want them in my res folders as I don't want them to end up in my final .apk file.

I want to do something similar to this question but using the newly added (in Gradle 1.1) unit test support (as opposed to instrumentation test).

My project structure is as follows:

/app
   /src
      /main
         /java/my.module/myClass.java
         /res/production_resources_go_here
      /test
         /java/my.module/myClassTest.java
         /resources/testFile.txt

what should my myClassTest test look like to be able to successfully read the testFile.txt?