* `actual` {any}

* `expected` {any}

* `message` {string|Error}

* `operator` {string} **Default:** `'!='`

* `stackStartFn` {Function} **Default:** `assert.fail`

If `message` is falsy, the error message is set as the values of `actual` and

`expected` separated by the provided `operator`. If just the two `actual` and

`expected` arguments are provided, `operator` will default to `'!='`. If

* `emitter` {EventEmitter} The emitter to query

* `eventName` {string|symbol} The event name

A class method that returns the number of listeners for the given `eventName`

registered on the given `emitter`.

* `filename` {string} Filename to be used to construct the relative require

```js

const { createRequireFromPath } = require('module');

const requireUtil = createRequireFromPath('../src/utils/');

* `keyword` {string} the potential keyword to parse and execute

* `rest` {any} any parameters to the keyword command

* Returns: {boolean}

An internal method used to parse and execute `REPLServer` keywords.

Returns `true` if `keyword` is a valid keyword, otherwise `false`.

* `target` {Object}

* `source` {Object}

The `util._extend()` method was never intended to be used outside of internal

Node.js modules. The community found and used it anyway.