Use the ending of the template name to infer response's Content-Type header.

def get_mimetype(self):
        """
        Use the ending of the template name to infer response's Content-Type header.
        """
        template_name = self.get_template_names()[0]
        for extension, mimetype in turrentine_settings.TURRENTINE_MIMETYPE_EXTENSIONS:
            if template_name.endswith(extension):
                return mimetype
        return 'text/html'