### Question:
Feature extends Observable { public String getId() { return mId; } Feature(Geometry featureGeometry, String id,
                   Map<String, String> properties); Iterable<String> getPropertyKeys(); Iterable getProperties(); String getProperty(String property); String getId(); boolean hasProperty(String property); Geometry getGeometry(); boolean hasProperties(); boolean hasGeometry();  }### Answer:
@Test public void testGetId() { Feature feature = new Feature(null, "Pirate", null); assertNotNull(feature.getId()); assertEquals("Pirate", feature.getId()); feature = new Feature(null, null, null); assertNull(feature.getId()); }