code: @Internal
  	public static void initializeSafetyNetForThread() {
  		SafetyNetCloseableRegistry oldRegistry = REGISTRIES.get();
  
  		checkState(null == oldRegistry, "Found an existing FileSystem safety net for this thread: %s " +
  				"This may indicate an accidental repeated initialization, or a leak of the" +
  				"(Inheritable)ThreadLocal through a ThreadPool.", oldRegistry);
  
  		SafetyNetCloseableRegistry newRegistry = new SafetyNetCloseableRegistry();
  		REGISTRIES.set(newRegistry);
  	}
docs: Activates the safety net for a thread. {@link FileSystem} instances obtained by the thread
  that called this method will be guarded, meaning that their created streams are tracked and can
  be closed via the safety net closing hook.
  
  <p>This method should be called at the beginning of a thread that should be guarded.
  
  @throws IllegalStateException Thrown, if a safety net was already registered for the thread.