1. Write a class called DOMStore that stores a Node and a value (reimplement Map). DOMStore contains the following functions:\n```javascript\nhas(node) // returns boolean\nget(node) // returns node or undefined\nset(node, value) // "upsert", update or insert\n```\n2. Flatten an array with unknown depth (reimplement .flat(Infinity)).\n  a. Write it both recursively and iteratively.

Write a class called DOMStore that stores a Node and a value (reimplement Map). DOMStore contains the following functions:\njavascript\nhas(node) // returns boo