code: static Executor makeContextAware(Executor delegate, CurrentTraceContext currentTraceContext) {
      class TracingCurrentRequestContextExecutor implements Executor {
        @Override public void execute(Runnable task) {
          delegate.execute(RequestContext.current().makeContextAware(currentTraceContext.wrap(task)));
        }
      }
      return new TracingCurrentRequestContextExecutor();
    }
docs: Decorates the input such that the {@link RequestContext#current() current request context} and
  the and the {@link CurrentTraceContext#get() current trace context} at assembly time is made
  current when task is executed.