\*\* EDITED \*\* 
For a given javascript function X 

```
X=function(obj){
  /* code here */
}

```

How do i modify the function X such that

```
i1=new X({a:1,b:2});
i1.c=3;

console.log(i1) to output as -> {a:1,b:2} 

```

thereby ignoring the externally added property 'c'