code: public static BucketTimer get(Id id, BucketFunction f) {
      return get(Spectator.globalRegistry(), id, f);
    }
docs: Creates a timer object that manages a set of timers based on the bucket
  function supplied. Calling record will be mapped to the record on the appropriate timer.
  
  @param id
  Identifier for the metric being registered.
  @param f
  Function to map values to buckets.
  @return
  Timer that manages sub-timers based on the bucket function.