def from_args(self, headers=None, url=None, filename=None, body=None):
        """Guess the most appropriate Response class based on
        the given arguments."""
        cls = Response
        if headers is not None:
            cls = self.from_headers(headers)
        if cls is Response and url is not None:
            cls = self.from_filename(url)
        if cls is Response and filename is not None:
            cls = self.from_filename(filename)
        if cls is Response and body is not None:
            cls = self.from_body(body)
        return cls
Guess the most appropriate Response class based on
        the given arguments.
stackoverflow/venv/lib/python3.6/site-packages/scrapy/responsetypes.py