I’m stuck on Cubic Minefield. I think i have the power function completed correctly, but it keeps returning an error that line 16 (function power(number, exponent) { ) has a Type Error: Can’t read protected property: findFriends. I’m really can’t figure out what i should do. I’ve pasted what i have below. Any help would be greatly appreciated!

```
// This function returns the number multiplied by the times
function mult(number, times) {
var total = 0;
while (times > 0) {
total += number;
times--;
}
return total;
}
// This function returns the number to the exponent power.
function power(number, exponent) {
var total = 1;
while (exponent > 0) {
total *= number;
exponent--;
}
return total;
}
// Don't change the follow code
var tower = this.findFriends()[0];
var a = tower.a;
var b = tower.b;
var c = tower.c;
var d = tower.d;
var x = hero.pos.x;
while (true) {
var y = a * power(x, 3) + b * power(x, 2) + c * power(x, 1) + d * power(x, 0);
hero.moveXY(x, y);
x = x + 5;
}
```