private void closeIfPossible() throws IOException {
    if (deprecated && activeInstanceCount.get() == 0) {
      close();
    }
  }
If this classloader is marked as deprecated, then this classloader can be closed after all
instances that use this classloader are closed.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/pipe/agent/plugin/service/PipePluginClassLoader.java