### Question:
ResourceModelStatistics { public ResourceModelStatistics countInstantiation() { ++this.instantiations; return this; } ResourceModelStatistics(); ResourceModelStatistics countInstantiation(); ResourceModelStatistics countSubsequentMapping(); ResourceModelStatistics countCacheHit(); ResourceModelStatistics countMappingDuration(int durationInMs);  }### Answer:
@Test public void testInstantiationCount() { assertNumberOfInstantiationsIs(0); countInstantiation(); assertNumberOfInstantiationsIs(1); countInstantiation(); assertNumberOfInstantiationsIs(2); }