A higher-order function is a function that does at least one of the following:

* Take one or more functions as an input
* Output a function

All other functions are first order functions. [1]

Unlike many other languages with imperative features, JavaScript allows you to utilize higher-order functions because it has "first-class functions". This means functions can be treated just like any other value in JavaScript: just like Strings or Numbers, Function values can be stored as variables, properties on objects or passed to other functions as arguments. Function values are actually Objects (inheriting from `Function.prototype`) so you can even add properties and store values on them, just like any regular Object.

The key difference between Functions and other value types in JavaScript is the call syntax: if a reference to a function is followed by parenthesis and some optional comma-separated values: `someFunctionValue(arg1, arg2, etc)`, then the function body will be executed with the supplied arguments (if any).

In this exercise we're going to demonstrate that functions can be passed as values by passing you a function as an argument.

# Task

Implement a function that takes a function as its first argument, a number `num` as its second argument, then executes the passed in function `num` times.

Use the boilerplate code given to you below to get started. Most/all future exercises will provide boilerplate.

## Arguments

* operation: A Function, takes no arguments, returns no useful value.
* num: the number of times to call `operation`

## Resources

* https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions_and_function_scope
* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/prototype

## Hints

* Don't overthink it, the code should be rather simple.
* It's ok to use a loop in your implementation, bonus points if you use recursion instead.
* You may notice some output. That is coming from the function we passed you.
* You do not need to console.log anything.

## Boilerplate

```js
function repeat(operation, num) {
  // SOLUTION GOES HERE
}

// Do not remove the line below
module.exports = repeat
```