server_urls = {url for url in urls if url}

            async def openapi(req: Request) -> JSONResponse:
                root_path = req.scope.get("root_path", "").rstrip("/")
                if root_path not in server_urls:
                    if root_path and self.root_path_in_servers:
                        self.servers.insert(0, {"url": root_path})

        # if a "form feed" character (page break) is found in the description text,
        # truncate description text to the content preceding the first "form feed"
        self.description = self.description.split("\f")[0].strip()
        response_fields = {}
        for additional_status_code, response in self.responses.items():
            assert isinstance(response, dict), "An additional response must be a dict"

* ♻ Strip empty whitespace from description extracted from docstrings. PR [#2821](https://github.com/tiangolo/fastapi/pull/2821) by [@and-semakin](https://github.com/and-semakin).