function isWebWorker() {
	return (
		// Check that we are not running in a Node.js runtime:
		IS_NODE === false &&

		// Check for presence of `WorkerGlobalScope` global variable:
		typeof WorkerGlobalScope === 'object' &&

		// Check for presence of `WorkerNavigator` global variable:
		isObject( WorkerNavigator ) &&

		// Check that the `navigator` global object is an instance of `WorkerNavigator`:
		navigator instanceof WorkerNavigator &&

		// Check for presence of `WorkerLocation` global variable:
		isObject( WorkerLocation ) &&

		// Check that the `location` global object is an instance of `WorkerLocation`:
		location instanceof WorkerLocation &&

		// Check for presence of `self` variable:
		typeof self === 'object' &&

		// Check that the `self` variable matches the determined global variable:
		self === Global &&

		// Check that the `self` variable is equal to the global scope:
		globalScope === true &&

		// Check for presence of `importScripts` function:
		typeof importScripts === 'function'
	);
}
Returns a boolean indicating if the runtime is a web worker.

@returns {boolean} boolean indicating if runtime is a web worker

@example
var bool = isWebWorker();
// returns <boolean>