20 var target = {};  variable
21 var handler = { isExtensible (target) {  argument
25 var proxy = new Proxy(target, handler);
52 var target = {};
54 var proxy = new Proxy(target, handler);
55 assert(Object.isExtensible(target) === true)
57 Object.preventExtensions(target);
58 assert(Object.isExtensible(target) === false);
62 var target = {};
64 var proxy = new Proxy(target, handler);
65 assert(Object.isExtensible(target) === true)
67 Object.preventExtensions(target);
68 assert(Object.isExtensible(target) === false);
72 var target = {};
74 var proxy = new Proxy(target, handler);
84 var target = { prop1: true };  variable
86   isExtensible(target) {  argument
87     target.prop1 = false;
88     return Object.isExtensible(target);
92 var proxy = new Proxy(target, handler);
94 assert(target.prop1 === false);
95 Object.preventExtensions(target);
96 assert(Object.isExtensible(target) === false);
100 var target = {};
102   isExtensible(target) {  argument
107 var proxy = new Proxy(target, handler);
117 var target = {};
119   isExtensible (target) {  argument
120     return Object.isExtensible(target);
124 var revocable = Proxy.revocable (target, {});
136 var target = {};
138   isExtensible(target) {  argument
139     return Object.isExtensible(target);
144   isExtensible(target) {  argument
149 var proxy = new Proxy(target, handler1);
163 Object.preventExtensions(target);