in invoker/core/src/main/java/com/google/cloud/functions/invoker/BackgroundFunctionExecutor.java [387:395]
private void runWithContextClassLoader(ContextClassLoaderTask task) throws Exception {
ClassLoader oldLoader = Thread.currentThread().getContextClassLoader();
try {
Thread.currentThread().setContextClassLoader(functionExecutor.functionClassLoader());
task.run();
} finally {
Thread.currentThread().setContextClassLoader(oldLoader);
}
}