public synchronized void release() throws IOException {
    activeInstanceCount.decrementAndGet();
    closeIfPossible();
  }
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