```js demo
function throttle(func, ms) {

  let isThrottled = false,
    savedArgs,
    savedThis;

  function wrapper() {

    if (isThrottled) { // (2)
      savedArgs = arguments;
      savedThis = this;
      return;
    }

    func.apply(this, arguments); // (1)

    isThrottled = true;

    setTimeout(function() {
      isThrottled = false; // (3)
      if (savedArgs) {
        wrapper.apply(savedThis, savedArgs);
        savedArgs = savedThis = null;
      }
    }, ms);
  }

  return wrapper;
}
```

A call to `throttle(func, ms)` returns `wrapper`.

1. During the first call, the `wrapper` just runs `func` and sets the cooldown state (`isThrottled = true`).
2. In this state all calls memorized in `savedArgs/savedThis`. Please note that both the context and the arguments are equally important and should be memorized. We need them simultaneously to reproduce the call.
3. ...Then after `ms` milliseconds pass, `setTimeout` triggers. The cooldown state is removed (`isThrottled = false`). And if we had ignored calls, then `wrapper` is executed with last memorized arguments and context.

The 3rd step runs not `func`, but `wrapper`, because we not only need to execute `func`, but once again enter the cooldown state and setup the timeout to reset it.