shape-of-myHeart

let keyMap = obj => (callback, formatter) => {
    let keys = Object.keys(obj),
        result = [];

    for (let i = 0; i < keys.length; i++) {
        let key = keys[i];
        result[typeof formatter === 'function' ? formatter(key) : i] = callback(obj[key], key);
    }

    return result;

shape-of-myHeart

const { Vector2, isVector2 } = (
    () => {
        class _Vector2 {
            constructor(x, y) {
                let data = {
                    x: x || 0,
                    y: y || 0
                };

                const checkParmeterType = parameters => {