### Question:
IndexPersistenceMgr { void close() throws IOException { fileInfoBackingCache.closeAllWithoutFlushing(); writeFileInfoCache.invalidateAll(); readFileInfoCache.invalidateAll(); } IndexPersistenceMgr(int pageSize,
                               int entriesPerPage,
                               ServerConfiguration conf,
                               SnapshotMap<Long, Boolean> activeLedgers,
                               LedgerDirsManager ledgerDirsManager,
                               StatsLogger statsLogger); @VisibleForTesting static final String getLedgerName(long ledgerId); ByteBuf getExplicitLac(long ledgerId); LedgerCache.LedgerIndexMetadata readLedgerIndexMetadata(long ledgerId);  }### Answer:
@Test public void testFileInfosOfVariousHeaderVersions() throws Exception { IndexPersistenceMgr indexPersistenceMgr = null; try { indexPersistenceMgr = createIndexPersistenceManager(1); long ledgerIdWithVersionZero = 25L; validateFileInfo(indexPersistenceMgr, ledgerIdWithVersionZero, FileInfo.V0); long ledgerIdWithVersionOne = 135L; validateFileInfo(indexPersistenceMgr, ledgerIdWithVersionOne, FileInfo.V1); } finally { if (null != indexPersistenceMgr) { indexPersistenceMgr.close(); } } }