    @Test
    public void testSetFocusListener(){

        class FocusHolder{
            double focus;
            @Subscribe public void set(MuseHandler.FocusReading reading){
                this.focus = reading.getFocus();
            }
        }
        FocusHolder holder = new FocusHolder();

        this.eventBus.register(holder);
        this.museHandler.setFocusListener();
        MuseDataPacket packet = PowerMockito.mock(MuseDataPacket.class);

        ArrayList<Double> values = new ArrayList<>(1);
        //add values to match sizes so we're sure the value to add fits
        values.add(1.5);


        //mock calls
        Mockito.when(packet.getPacketType()).thenReturn(MuseDataPacketType.CONCENTRATION);
        Mockito.when(packet.getValues()).thenReturn(values);

        this.museHandler.getFocusListener().receiveMuseDataPacket(packet);
        assertEquals("The focus", holder.focus,1.5,0.);

    }