Merge default.

--HG--
branch : key-processing

common/modules/base.jsm

@@ -758,6 +758,7 @@ Class.memoize = function memoize(getter)
             this.get = function replace() let (obj = this.instance || this) (
                 Class.replaceProperty(obj, key, null),
                 Class.replaceProperty(obj, key, getter.call(this, key)))
+            this.set = function replace(val) Class.replaceProperty(this.instance || this, val);
         }
     });