iter_recorded() method fails to iterate if all the values are zero.

iter_recorded() won't work when all the values recorded by the Histogram instance is 0.
Sample code to hit the issue:

let mut tracker = Histogram::<u64>::new(3).unwrap();
tracker += 0;
tracker += 0;
tracker += 0;

 // print 3 as expected.
 println!("{}", tracker.len());

 let mut res = String::new();
 for v in tracker.iter_recorded() {
     res.push_str(format!("value {} and count {}", v.value_iterated_to(), v.count_at_value()).as_str());
 }

 // nothing is printed. Expected: value 0 and count 3
 println!("{}", res);

We use the iterator to print out a certain format and emit to our log file. Is there a better way to do that for the logging purpose?

Start with the iter_recorded() entry point and reproduce the provided Histogram example with three zero values. Trace why the iterator emits nothing, then verify that the completed behavior reports value 0 with count 3 and preserves iteration for other recorded values.