### Question:
PolicyWriterUtil { public static boolean writeClassMap(@Nonnull final ClassMap classMap, final PolicyManagerImpl.PolicyMapLocation policyMapLocation) { boolean result = true; final DataBroker mountpoint = policyMapLocation.getMountpoint(); final NodeId nodeId = policyMapLocation.getNodeId(); final InstanceIdentifier<ClassMap> classMapIid = classMapInstanceIdentifier(classMap); netconfWrite(mountpoint, classMapIid, classMap); final java.util.Optional<ClassMap> checkCreated = java.util.Optional.ofNullable(netconfRead(mountpoint, classMapIid)); if (checkCreated.isPresent()) { LOG.trace("Created class-map {} on node {}", classMap.getName(), nodeId.getValue()); } else { LOG.warn("Failed to create class-map {} on node {}", classMap.getName(), nodeId.getValue()); result = false; } return result; } private  PolicyWriterUtil(); static boolean writeClassMap(@Nonnull final ClassMap classMap,
                                        final PolicyManagerImpl.PolicyMapLocation policyMapLocation); static boolean removeClassMap(final ClassMap classMap, final PolicyManagerImpl.PolicyMapLocation location); static boolean writePolicyMap(final PolicyMap policyMap, final PolicyManagerImpl.PolicyMapLocation location); static boolean removePolicyMap(final PolicyManagerImpl.PolicyMapLocation location); static boolean writePolicyMapEntry(final Class policyMapEntry,
                                              final PolicyManagerImpl.PolicyMapLocation location); static boolean removePolicyMapEntry(final Class policyMapEntry, final PolicyManagerImpl.PolicyMapLocation location); static boolean writeInterface(final PolicyManagerImpl.PolicyMapLocation location); static boolean removeInterface(final PolicyManagerImpl.PolicyMapLocation location); static boolean writeRemote(final ServiceFfName remoteForwarder,
                                      final PolicyManagerImpl.PolicyMapLocation location); static boolean removeRemote(final ServiceFfName remoteForwarder, final PolicyManagerImpl.PolicyMapLocation location); static boolean writeServicePath(final ServiceChain serviceChain,
                                           final PolicyManagerImpl.PolicyMapLocation location); static boolean removeServicePath(final ServiceChain serviceChain, final PolicyManagerImpl.PolicyMapLocation location); static InstanceIdentifier<PolicyMap> policyMapInstanceIdentifier(final String policyMapName); static InstanceIdentifier<ServicePolicy> interfaceInstanceIdentifier(final String ethernetName); static U netconfRead(final DataBroker mountpoint,
                                                       final InstanceIdentifier<U> readIID);  }### Answer:
@Test public void testWriteClassMap() throws Exception { LOG.debug("scenario: fail with one entry, no writeOnlyTransaction"); final ClassMap classMap = new ClassMapBuilder().setName(UNIT_CLASS_MAP_ENTRY_NAME).build(); assertFalse(PolicyWriterUtil.writeClassMap(classMap, getLocation())); LOG.debug("scenario: fail with one entry, available writeOnlyTransaction, no readOnlyTransaction"); PowerMockito.stub(PowerMockito.method(NetconfTransactionCreator.class, NETCONF_WRITE_ONLY_TRANSACTION)).toReturn(wTxOptional); when(wTx.submit()).thenReturn(Futures.immediateCheckedFuture(null)); assertFalse(PolicyWriterUtil.writeClassMap(classMap, getLocation())); LOG.debug("scenario: succeed with one entry, available writeOnlyTransaction, available readOnlyTransaction"); PowerMockito.stub(PowerMockito.method(NetconfTransactionCreator.class, NETCONF_READ_ONLY_TRANSACTION)).toReturn(rTxOptional); when(rTx.read(eq(LogicalDatastoreType.CONFIGURATION), Matchers.<InstanceIdentifier<ClassMap>>any())) .thenReturn(Futures.immediateCheckedFuture(Optional.of( new ClassMapBuilder().setName(CLASS_MAP_NAME).build()))); assertTrue(PolicyWriterUtil.writeClassMap(classMap, getLocation())); LOG.debug("scenario: fail with one entry, available writeOnlyTransaction, available readOnlyTransaction, check->null"); PowerMockito.stub(PowerMockito.method(PolicyWriterUtil.class, NETCONF_READ)).toReturn(null); assertFalse(PolicyWriterUtil.writeClassMap(classMap, getLocation())); }