@Test
  public void should_not_crashOnDeletedSensor() throws Exception {
    // given
    SensorEvent event =
        new SensorEvent("CERN", "LHC", "Siggh boson", "SB", "number", "#", 1, 2, 3, 4, 5, 10);
    sessionManager.onEvent(event);

    // when
    sessionManager.deleteSensorStream(event.getSensorName());

    // then (shouldn't crash)
    sessionManager.onEvent(event);
  }
  @Test
  public void shouldCreateAStreamForEachSensor() {
    sessionManager.startMobileSession(false);

    triggerMeasurement();
    SensorEvent event =
        new SensorEvent("CERN", "LHC2", "Siggh boson", "SB", "number", "#", 1, 2, 3, 4, 5, 10);
    sessionManager.onEvent(event);

    MeasurementStream expected = event.stream();
    assertThat(sessionManager.getMeasurementStreams(), hasItem(expected));
  }
  private void triggerMeasurement(String name, double value) {

    lastEvent = New.sensorEvent(name, value);
    sessionManager.onEvent(lastEvent);
  }