install gulp

user/themes/anissabensalah/node_modules/es6-symbol/validate-symbol.js

@@ -0,0 +1,8 @@
+'use strict';
+
+var isSymbol = require('./is-symbol');
+
+module.exports = function (value) {
+	if (!isSymbol(value)) throw new TypeError(value + " is not a symbol");
+	return value;
+};