### Question:
DiskLruCache implements Closeable { public synchronized boolean remove(String key) throws IOException { checkNotClosed(); Entry entry = lruEntries.get(key); if (entry == null || entry.currentEditor != null) { return false; } for (int i = 0; i < valueCount; i++) { File file = entry.getCleanFile(i); if (file.exists() && !file.delete()) { throw new IOException("failed to delete " + file); } size -= entry.lengths[i]; entry.lengths[i] = 0; } redundantOpCount++; journalWriter.append(REMOVE); journalWriter.append(' '); journalWriter.append(key); journalWriter.append('\n'); lruEntries.remove(key); if (journalRebuildRequired()) { executorService.submit(cleanupCallable); } return true; } private  DiskLruCache(File directory, int appVersion, int valueCount, long maxSize); static DiskLruCache open(File directory, int appVersion, int valueCount, long maxSize); synchronized Value get(String key); Editor edit(String key); File getDirectory(); synchronized long getMaxSize(); synchronized void setMaxSize(long maxSize); synchronized long size(); synchronized boolean remove(String key); synchronized boolean isClosed(); synchronized void flush(); synchronized void close(); void delete();  }### Answer:
@Test public void removeAbsentElement() throws Exception { cache.remove("a"); }