def from_headers(self, headers):
        """Return the most appropriate Response class by looking at the HTTP
        headers"""
        cls = Response
        if b'Content-Type' in headers:
            cls = self.from_content_type(
                content_type=headers[b'Content-type'],
                content_encoding=headers.get(b'Content-Encoding')
            )
        if cls is Response and b'Content-Disposition' in headers:
            cls = self.from_content_disposition(headers[b'Content-Disposition'])
        return cls
Return the most appropriate Response class by looking at the HTTP
        headers
stackoverflow/venv/lib/python3.6/site-packages/scrapy/responsetypes.py