proxytest.js

var myObject = {
  "foo": true,
  "author": "simon",
  "env": 123
}

var myProxy = new JavaAdapter(org.mozilla.javascript.NativeObject, {
  // The "start" argument is here for setters and getters living
  // on a prototype, so they know what to use as "this"-object.
  put: function(name, start, value) {
      myObject[name] = value;
  },
  get: function(name, start) {
     return myObject[name];
  }
});

print(myProxy.author)