* `url`: The URL for the target documentation. Value MUST be in
                        the form of a URL.

                Read more in the
                [FastAPI docs for Metadata and Docs URLs](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-tags).

                **Example**

                ```python
                from fastapi import FastAPI

                tags_metadata = [

        self.description = description or inspect.cleandoc(self.endpoint.__doc__ or "")
        # 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():