首次放到 git

utils/properties.js

@@ -0,0 +1,22 @@
+'use strict';
+
+function defineProperty(object, name, value) {
+    Object.defineProperty(object, name, {
+        enumerable: true,
+        value: value,
+        writable: false,
+    });
+}
+
+function defineFrozen(object, name, value) {
+    var frozen = JSON.stringify(value);
+    Object.defineProperty(object, name, {
+        enumerable: true,
+        get: function() { return JSON.parse(frozen); }
+    });
+}
+
+module.exports = {
+    defineFrozen: defineFrozen,
+    defineProperty: defineProperty,
+};