def test_explicitRangeOverlappingEnd(self):
        """
        A correct response to a bytes range header request from A to B when B
        is past the end of the resource starts with the A'th byte and ends
        with the last byte of the resource. The first byte of a page is
        numbered with 0.
        """
        self.request.requestHeaders.addRawHeader(b'range', b'bytes=40-100')
        self.resource.render(self.request)
        written = b''.join(self.request.written)
        self.assertEqual(written, self.payload[40:])
        self.assertEqual(self.request.responseCode, http.PARTIAL_CONTENT)
        self.assertEqual(
            self.request.responseHeaders.getRawHeaders(b'content-range')[0],
            b'bytes 40-63/64')
        self.assertEqual(
            intToBytes(len(written)),
            self.request.responseHeaders.getRawHeaders(b'content-length')[0])

        A correct response to a bytes range header request from A to B when B
        is past the end of the resource starts with the A'th byte and ends
        with the last byte of the resource. The first byte of a page is
        numbered with 0.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_static.py