```javascript
var iterations = 1000000;

var x = {action: "REDUX_ACTION", state: 1};
var y = {state: 666};

function doSomething(){
    // return Object.assign(x, y); // create new object by ECMAScript (ES6) assign() method
    // return {...x, state: y.state}; // create new object by destructuring operator
}
console.error("Valid result is: ",doSomething());

var time_start = performance.now();
for(i=1; i<iterations; i++){
    doSomething();
}
var time_end = performance.now();

console.warn("Call the function took " + (time_end - time_start) + " milliseconds.");
```