def select_jinja_autoescape(self, filename: str) -> bool:
        """Returns ``True`` if autoescaping should be active for the given
        template name. If no template name is given, returns `True`.

        .. versionchanged:: 2.2
            Autoescaping is now enabled by default for ``.svg`` files.

        .. versionadded:: 0.5
        """
        if filename is None:
            return True
        return filename.endswith((".html", ".htm", ".xml", ".xhtml", ".svg"))
Returns ``True`` if autoescaping should be active for the given
        template name. If no template name is given, returns `True`.

        .. versionchanged:: 2.2
            Autoescaping is now enabled by default for ``.svg`` files.

        .. versionadded:: 0.5
        
src/flask/sansio/app.py