A Function instance that is not a Class
plain-function/is
Confirms if given object is a plain function
```javascript const isPlainFunction = require("type/plain-function/is");
isPlainFunction(function () {}); // true isPlainFunction(() => {}); // true isPlainFunction(class {}); // false isPlainFunction("foo"); // false ```
plain-function/ensure
If given argument is a plain function object, it is returned back. Otherwise TypeError
is thrown.
```javascript const ensurePlainFunction = require("type/function/ensure");
const fn = function () {}; ensurePlainFunction(fn); // fn ensurePlainFunction(class {}); // Thrown TypeError: class is not a plain function ```