What does the `requote_uri` function do in the Requests library, and why is it the first step to disable encoding?

The `requote_uri` function in `requests/utils.py` passes the URI through an unquote/quote cycle using the `quote()` call, which percent‑encodes illegal characters like `{` to `%7B`. By commenting out the call to `requote_uri` in `models.py`, you stop the Requests library from applying its default encoding, leaving the raw URL intact as needed for exploit testing.