title: How to mock method in extended trait with Mockito
body: <p>How can I mock dependend traits with mockito?
  I have two traits: </p>
  
  <pre><code> trait A {
      def a = 1
    }
  
    trait B extends A {
      def b = {
        // do things
        a
        // do things
      }
    }
  </code></pre>
  
  <p>Now, I want to test Trait B. And I want to verify, that A.a() gets called:</p>
  
  <pre><code>class SmallTest extends FunSuite with MockitoSugar {
    test("prove, that a gets called") {
      val mockA = mock[A]
      val b = new B with mockA {}  // This won't compile
      b.b
      verify(mockA).a
    }
  }
  </code></pre>
  
  <p>This example won't compile. But how would I "inject" my mock otherwise?</p>