Design Browser History

Design a browser history. You start on the `homepage`, and you can visit new URLs, move back, and move forward. - `visit(url)` navigates to `url` from the current page and clears all forward history. - `back(steps)` moves back `steps` pages in history. If you can only move back fewer than `steps` pages, stop at the oldest page. Returns the current url after moving. - `forward(steps)` moves forward `steps` pages. If you can only move forward fewer than `steps` pages, stop at the newest page. Returns the current url after moving. Implement the function `browserHistory(homepage, operations)` where `homepage` is the starting url and `operations` is a list of `[op, ...args]`: `["visit", url]`, `["back", steps]`, `["forward", steps]`. For `"visit"` return `null`; for `"back"` and `"forward"` return the current url. Return the list of results, one per operation (use null for operations that return nothing).