Implement debounce and throttle from scratch — including leading/trailing edge options, cancellation, and the closure mechanics that make them work.

Imagine you're pressing a button that makes a toy pop up. If you press it many times fast, debounce waits until you stop pressing for a little while, then pops the toy once. Throttle is like a timer that only lets the toy pop once every few seconds, no matter how many times you press.