### Question:
FileTxnLog implements TxnLog, Closeable { public static void setPreallocSize(long size) { FilePadding.setPreallocSize(size); } FileTxnLog(File logDir); static void setPreallocSize(long size); @Override synchronized void setServerStats(ServerStats serverStats); static void setTxnLogSizeLimit(long size); synchronized long getCurrentLogSize(); synchronized void setTotalLogSize(long size); synchronized long getTotalLogSize(); synchronized void rollLog(); synchronized void close(); synchronized boolean append(TxnHeader hdr, Record txn); @Override synchronized boolean append(TxnHeader hdr, Record txn, TxnDigest digest); static File[] getLogFiles(File[] logDirList, long snapshotZxid); long getLastLoggedZxid(); synchronized void commit(); long getTxnLogSyncElapsedTime(); TxnIterator read(long zxid); TxnIterator read(long zxid, boolean fastForward); boolean truncate(long zxid); long getDbId(); boolean isForceSync(); static final int TXNLOG_MAGIC; static final int VERSION; static final String LOG_FILE_PREFIX; }### Answer:
@Test public void testSetPreallocSize() { long customPreallocSize = 10101; FileTxnLog.setPreallocSize(customPreallocSize); assertThat(FilePadding.getPreAllocSize(), is(equalTo(customPreallocSize))); }