gistfile1.js

// Extension-side code
let AnObj = {

    field: "hello",

    thisIsATest: function() {
        let str = this.field + " world!";
        return str;
    },
};

let thisIsATestBound = AnObj.thisIsATest.bind(AnObj);

Components.utils.exportFunction(AnObj.thisIsATest, window,
                                {defineAs: "thisIsATest"});


Components.utils.exportFunction(thisIsATestBound, window,
                                {defineAs: "thisIsATestBound"});



// User-side code
console.log(thisIsATest()); // "undefined world!"
console.log(thisIsATestBound()); // "hello world!"