Update to NPM version

ProjectSourceCode/node_modules/is-weakref/index.js

@@ -0,0 +1,21 @@
+'use strict';
+
+var callBound = require('call-bind/callBound');
+
+var $deref = callBound('WeakRef.prototype.deref', true);
+
+module.exports = typeof WeakRef === 'undefined'
+	? function isWeakRef(value) { // eslint-disable-line no-unused-vars
+		return false;
+	}
+	: function isWeakRef(value) {
+		if (!value || typeof value !== 'object') {
+			return false;
+		}
+		try {
+			$deref(value);
+			return true;
+		} catch (e) {
+			return false;
+		}
+	};