Here's an example of the use of this trait to test the ArrayBlockingQueue concurrency abstraction from java.util.concurrent:

 import org.scalatest.FunSuite
 import org.scalatest.concurrent.ConductorMethods
 import org.scalatest.matchers.ShouldMatchers
 import java.util.concurrent.ArrayBlockingQueue

 class ArrayBlockingQueueSuite extends FunSuite with ConductorMethods with ShouldMatchers {
 
   test("calling put on a full queue blocks the producer thread") {

     val buf = new ArrayBlockingQueue[Int](1)
 
     thread("producer") {
       buf put 42
       buf put 17
       beat should be (1)
     }
 
     thread("consumer") {
       waitForBeat(1)
       buf.take should be (42)
       buf.take should be (17)
     }
 
     whenFinished {
       buf should be ('empty)
     }
   }

   test("calling take on an empty queue blocks the consumer thread") {

     val buf = new ArrayBlockingQueue[Int](1)

     thread("producer") {
       waitForBeat(1)
       buf put 42
       buf put 17
     }

     thread("consumer") {
       buf.take should be (42)
       buf.take should be (17)
       beat should be (1)
     }

     whenFinished {
       buf should be ('empty)
     }
   }
 }
 

For an explanation of how these tests work, see the documentation for Conductor.