golang-github-nozzle-throttler-dev 1.1-4 (amd64 binary) in ubuntu oracular

 The API is almost identical to WaitGroups,
 but it allows you to set a max number of workers that can be
 running simultaneously. It uses channels internally to block until a job
 completes by calling Done() or until all jobs have been completed. It
 also provides a built in error channel that captures your goroutine
 errors and provides access to them as []error after you exit the loop.