### Question:
NaturalKeyDescriptor { public NaturalKeyDescriptor() { this(null, null, null, null); } NaturalKeyDescriptor();  NaturalKeyDescriptor(Map<String, String> naturalKeys);  NaturalKeyDescriptor(Map<String, String> naturalKeys, String tenantId, String entityType, String parentId); @Override boolean equals(Object o); @Override int hashCode(); Map<String, String> getNaturalKeys(); void setNaturalKeys(Map<String, String> naturalKeys); String getTenantId(); void setTenantId(String tenantId); String getEntityType(); void setEntityType(String entityType); boolean isNaturalKeysNotNeeded(); void setNaturalKeysNotNeeded(boolean naturalKeysNotNeeded); String getParentId(); void setParentId(String parentId);  }### Answer:
@Test public void testNaturalKeyDescriptor() { NaturalKeyDescriptor naturalKeyDescriptor = new NaturalKeyDescriptor(); Map<String, String> naturalKeys = naturalKeyDescriptor.getNaturalKeys(); assertNotNull("naturalKeys is not null", naturalKeys); assertEquals("naturalKeys has 0 natural keys", 0, naturalKeys.size()); assertEquals("tenantId is empty", "", naturalKeyDescriptor.getTenantId()); assertEquals("entityType is empty", "", naturalKeyDescriptor.getEntityType()); NaturalKeyDescriptor naturalKeyDescriptor2 = new NaturalKeyDescriptor(); assertTrue(naturalKeyDescriptor.equals(naturalKeyDescriptor2)); }