'Guess the most appropriate Response class based on
the given arguments.'

def from_args(self, headers=None, url=None, filename=None, body=None):

    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
