### Question:
MetricDescriptorCache { public String idToDescriptorType(Id id) { return baseStackdriverMetricTypeName + id.name(); } MetricDescriptorCache(ConfigParams configParams); String idToDescriptorType(Id id); Map<String, String> getExtraTimeSeriesLabels(); void addExtraTimeSeriesLabel(String key, String value); String meterToKind(Registry registry, Meter meter); Map<String, String> tagsToTimeSeriesLabels(String descriptorType, Iterable<Tag> tags); boolean meterIsTimer(Registry registry, Meter meter); String descriptorTypeToKind(String descriptorType, Registry registry, Meter meter); MetricDescriptor addLabel(String descriptorType, String newLabel); static final String INSTANCE_LABEL; }### Answer:
@Test public void descriptorTypeAreCompliant() { Assert.assertEquals( "custom.googleapis.com/TESTNAMESPACE/" + applicationName + "/idA", cache.idToDescriptorType(idA)); }