code: public UBench addTask(String name, Runnable task) {
          return putTask(name, () -> {
              long start = System.nanoTime();
              task.run();
              return System.nanoTime() - start;
          });
      }
docs: Include a named task that has no output value in to the benchmark.
  
  @param name
  The name of the task. Only one task with any one name is
  allowed.
  @param task
  The task to perform
  @return The same object, for chaining calls.