@After
  public void cleanup() throws IOException {
    File[] files = tempDir.listFiles();
    if (files == null) {
      throw new IOException("Could not list files in directory: " + tempDir.getAbsolutePath());
    }
    for (File file : files) {
      assertTrue(file + " could not be deleted", file.delete());
    }
  }
Deletes the temporary directory.
@throws IOException
ambry-server/src/test/java/com/github/ambry/server/StatsManagerTest.java