code: public void waitTillAllUpdatesExecuted() throws InterruptedException
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(tc, "waitTillAllUpdatesExecuted");
      synchronized (this)
      {
        while (enqueuedUnits.size() > 0 || executing)
        {
          try
          {
            this.wait();
          }
          catch (InterruptedException e)
          {
            // No FFDC code needed
            if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(tc, "waitTillAllUpdatesExecuted", e);
            throw e;
          }
        }
      }
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "waitTillAllUpdatesExecuted");
    }
docs: This method blocks till there are 0 enqueued updates and 0 executing updates.
  Useful for unit testing.