### Question:
ContextBuilder { public Context build() { final ContextImpl context = new ContextImpl(); context.readerCache = readerCache; context.matchup = matchup; context.observation = observation; context.targetVariable = targetVariable; context.dimensionConfiguration = dimensionConfiguration; context.configuration = configuration; return context; } ContextBuilder();   ContextBuilder(ReaderCache readerCache); ContextBuilder targetVariable(Variable targetVariable); ContextBuilder observation(Observation observation); ContextBuilder dimensionConfiguration(Map<String, Integer> dimensionConfiguration); ContextBuilder configuration(Configuration configuration); Context build();  }### Answer:
@Test public void testBuild_empty() { final ContextBuilder contextBuilder = new ContextBuilder(); final Context context = contextBuilder.build(); assertNotNull(context); assertNull(context.getConfiguration()); final Map<String, Integer> dimensionConfiguration = context.getDimensionConfiguration(); assertNotNull(dimensionConfiguration); assertEquals(0, dimensionConfiguration.size()); assertNull(context.getMatchup()); assertNull(context.getObservation()); assertNull(context.getObservationReader()); assertNull(context.getReferenceObservationReader()); assertNull(context.getTargetVariable()); }