### Question:
HttpUtils { static Double checkQuality(final Double quality, final String parameter) { if(quality==null) { return null; } checkQualityRange(quality, parameter); checkArgument(DoubleUtils.hasPrecision(quality,3),"%s cannot have more than 3 decimals (%s)",parameter,quality); return quality; } private  HttpUtils();   }### Answer:
@Test public void nullQualityIsValid() { assertThat(HttpUtils.checkQuality(null,"Weight"),nullValue()); }