has-flag
Check if argv has a specific flag
hasown
A robust, ES3 compatible, "has own property" predicate.
for-in
Iterate over the own and inherited enumerable properties of an object, and return an object with properties that evaluate to true from the callback. Exit early by returning `false`. JavaScript/Node.js
has-property-descriptors
Does the environment have full property descriptor support? Handles IE 8's broken defineProperty/gOPD.
has-proto
Does this environment have the ability to get the [[Prototype]] of an object on creation with `__proto__`?
