code: /** 
   * Test LRU Cache Eviction.
   * @throws InvalidPathException
   * @throws FileAlreadyExistException
   * @throws IOException
   */
  @Test public void isInMemoryTest2() throws InvalidPathException, FileAlreadyExistException, IOException {
    for (int k=0; k < MAX_FILES; k++) {
      int fileId=TestUtils.createByteFile(mTfs,"/file" + k,WriteType.MUST_CACHE,USER_QUOTA_UNIT_BYTES);
      TachyonFile file=mTfs.getFile(fileId);
      Assert.assertTrue(file.isInMemory());
    }
    CommonUtils.sleepMs(null,WORKER_TO_MASTER_HEARTBEAT_INTERVAL_MS);
    for (int k=0; k < MAX_FILES; k++) {
      TachyonFile file=mTfs.getFile("/file" + k);
      Assert.assertTrue(file.isInMemory());
    }
    for (int k=MAX_FILES; k < MAX_FILES + 1; k++) {
      int fileId=TestUtils.createByteFile(mTfs,"/file" + k,WriteType.MUST_CACHE,USER_QUOTA_UNIT_BYTES);
      TachyonFile file=mTfs.getFile(fileId);
      Assert.assertTrue(file.isInMemory());
    }
    CommonUtils.sleepMs(null,WORKER_TO_MASTER_HEARTBEAT_INTERVAL_MS);
    TachyonFile file=mTfs.getFile("/file" + 0);
    Assert.assertFalse(file.isInMemory());
    for (int k=1; k < MAX_FILES + 1; k++) {
      file=mTfs.getFile("/file" + k);
      Assert.assertTrue(file.isInMemory());
    }
  }
  