charlike/templates/node_modules/es6-set/valid-set.js

Small, fast, simple and streaming project scaffolder for myself, but not only. Supports hundreds of template engines through the @JSTransformers API or if you want custom `render` function passed through options

'use strict';

var isSet = require('./is-set');

module.exports = function (x) {
	if (!isSet(x)) throw new TypeError(x + " is not a Set");
	return x;
};