Using Guice Injection with flatspecs "behave" to share tests

Question

How can flatspecs behave be used in combination with guice and application injection?

In our installation, we see calls to the code below before the application is available and therefore the injector will not be there.

Basic example

it should behave like someControllerFunction(p1, p2, p3) {
   //This is the block of code that gets executed before the injector and application is setup !
   val classUnderTest = app.injector.instanceOf[ClassUnderTest]
   classUnderTest.method()(_)
}