DurationBuckets.exponential fails due to fractional nanoseconds

[evertlammerts]

DurationBuckets.exponential throws an IllegalArgumentException for large set of factors, because it is not possible to create a Duration based on a fractional nanosecond.:

java.lang.IllegalArgumentException: Unable to create a precise Duration with the specified factor

	at com.uber.m3.util.Duration.multiply(Duration.java:313)
	at com.uber.m3.tally.DurationBuckets.exponential(DurationBuckets.java:101)

The below code gives an idea of how I tried looking for a factor between 1 and 2 that can be used to create 20 buckets:

        BigDecimal curr = new BigDecimal("1.01");
        BigDecimal step = new BigDecimal("0.01");
        BigDecimal end = new BigDecimal("1.99");
        while (curr.compareTo(end) <= 0) {
            try {
                DurationBuckets.exponential(
                    Duration.ofMillis(1), curr.floatValue(), 20
                );
                System.out.println(curr);
            } catch (IllegalArgumentException e) {}
            curr = curr.add(step);
        }

None of them work. This virtually renders DurationBuckets.exponential useless.