I try to give a abroad picture from my question. Suppose I have a function, inside this function I have some other function calls and finally, first function returns a value.

```
function a() {
  return 1;
}

function b() {
  var result = a();
  return 2 + result;
}

b();

```

Now, after calling b() method, I want to know how many and what functions called inside the b() function. How can I achieve it?