### Question:
BackupProtocolService implements AutoCloseable { @Override public void close() throws Exception { pageCacheContianer.close(); } BackupProtocolService( Supplier<FileSystemAbstraction> fileSystemSupplier, LogProvider logProvider, OutputStream logDestination, Monitors monitors,
            BackupPageCacheContainer pageCacheContainer ); BackupOutcome doFullBackup( final String sourceHostNameOrIp, final int sourcePort, DatabaseLayout targetLayout,
                                       ConsistencyCheck consistencyCheck, Config tuningConfiguration,
                                       final long timeout, final boolean forensics ); BackupOutcome doIncrementalBackup(
            String sourceHostNameOrIp, int sourcePort, DatabaseLayout databaseLayout, ConsistencyCheck consistencyCheck,
            long timeout, Config config ); BackupOutcome doIncrementalBackupOrFallbackToFull( String sourceHostNameOrIp, int sourcePort,
                                                              DatabaseLayout targetLayout,
                                                              ConsistencyCheck consistencyCheck, Config config,
                                                              long timeout, boolean forensics ); static BackupOutcome doIncrementalBackup( String sourceHostNameOrIp, int sourcePort, GraphDatabaseAPI targetDb, long timeout ); @Override void close();  }### Answer:
@Test void closePageCacheContainerOnClose() throws Exception { PageCache pageCache = mock( PageCache.class ); BackupPageCacheContainer container = BackupPageCacheContainer.of( pageCache ); BackupProtocolService protocolService = new BackupProtocolService( EphemeralFileSystemAbstraction::new, NullLogProvider.getInstance(), NULL_OUTPUT_STREAM, new Monitors(), container ); protocolService.close(); verify( pageCache ).close(); }