Throttle (not debounce) a method - similar to lodash, but simpler

throttle.js

const throttle = (fn, delay) => { 
    let lastCall = 0 
    return (...args) => { 
        const now = (new Date).getTime() 
        if (now - lastCall < delay) return 
        lastCall = now 
        return fn(...args) 
    } 
}