static range(count) {
        if (!Number.isInteger(count) || count < 0) {
            throw new DetailedError("bad count", {count});
        }

        return Seq.fromGenerator(function*() {
            for (let i = 0; i < count; i++) {
                yield i;
            }
        });
    }
Returns a sequence of natural numbers, starting at 0 and incrementing until just before the given count.
@param {!int} count
@returns {!Seq.<!int>}