FrameBuffer { public boolean canPull() { return areAllTracksConfigured() && !frames.isEmpty(); } FrameBuffer(int numberOfTracks); void configure(int trackIndex); boolean areAllTracksConfigured(); void push(Frame frame); boolean canPull(); Frame pull(); void addTrack();  }
@Test public void canNotPull_UntilConfigured() { FrameBuffer frameBuffer = new FrameBuffer(1); assertFalse(frameBuffer.canPull()); }