String Challeng: How to convert seconds to HH:MM:SS

Lets see who can give me the best way to convert seconds(Long/Double) value and convert it to a string with format 'HH:MM:SS'. I currently use a microflow that’s giving me a cast error and the microflow is too long. I create, Hours, Minutes, Seconds then I convert them to string and append zeros if they are of length 1 output the concatenated string.
1 answers

Just brainstorming here, but how about creating a DateTime variable, setting it to the beginning of a day (which puts it at 00:00:00 time, I think?), then using addSeconds($variable, $seconds).

Then you could probably use formatTime or maybe even formatDateTime($variable, 'HH:mm:ss') on a string attribute.