@Test
public void numberItemShouldNotConvertUnitsWhereMeasurmentSystemEquals() {

    NumberItem item = mock(NumberItem.class);
    doReturn(Length.class).when(item).getDimension();
    QuantityType<Length> originalState = new QuantityType<>("100 cm");
    @SuppressWarnings("unchecked")
    QuantityType<Length> convertedState = (QuantityType<Length>) itemStateConverter
            .convertToAcceptedState(originalState, item);
    assertThat(convertedState.getUnit(), is(originalState.getUnit()));
}