@Test
public void shouldProvideAvgForEachStream() {
MeasurementStream stream = mock(MeasurementStream.class);
when(stream.getAvg()).thenReturn(10.0);
String name = sensor.getSensorName();
when(stream.getSensorName()).thenReturn(name);
sessionManager.session.add(stream);
assertThat(sessionManager.getAvg(sensor), equalTo(10.0));
}