A StreamHelper can be viewed as a pausable stream with some helper methods.
It is not a full featured stream like in nodejs (and can’t directly used as one)
but the exposed methods should be enough to write the glue code with other async
libraries : on('data', function), on('end', function) and on('error', function).
It starts paused, be sure to resume() it when ready.
If you are looking for an asynchronous helper without writing glue code, take a
look at accumulate(function).