Handling/creating hybrid errors. Hybrid middleware between callbacks and throws. Helpful util for modules that have hybrid APIs and want when they use promises, directly to throw the errors; when use callbacks to pass errors to first argument of this call
Converts result-first callbacks to classic (node.js-style) error-first callbacks with 3 lines of code. Useful when you want to promisify result-first APIs (like emitter.on). Inspired by [rfpify] and probably used in it.