@Test
  public void shouldProvidePeakForEachStream() {
    MeasurementStream stream = mock(MeasurementStream.class);
    when(stream.getPeak()).thenReturn(11.0);
    String name = sensor.getSensorName();
    when(stream.getSensorName()).thenReturn(name);
    sessionManager.session.add(stream);

    assertThat(sessionManager.getPeak(sensor), equalTo(11.0));
  }