Empty arguments middleware
Multiple option error middleware
Required option validation middleware
Error event middleware
Unknown option middleware
Option events middleware
Command executable middleware
Variable arguments middleware
Action callback middleware
Multiple option initialization middleware
Ready callback middleware
Stdin middleware
Run event middleware
Notify middleware
Color option middleware
Debug flag middleware
Argument parser middleware
Version option middleware
Flag option utilities
Description utility
Converter utility
Deprecation warning utility
Command invocation middleware
Canonical example for the command module
