Override inherited do_GET method.

        Include logic for returning a http manifest when the URL ends with
        "http_manifest.json".

def do_GET(self):
        """Override inherited do_GET method.

        Include logic for returning a http manifest when the URL ends with
        "http_manifest.json".
        """
        if self.path.endswith("http_manifest.json"):
            try:
                manifest = self.generate_http_manifest()
                self.send_response(200)
                self.end_headers()
                self.wfile.write(manifest)
            except dtoolcore.DtoolCoreTypeError:
                self.send_response(400)
                self.end_headers()

        else:
            super(DtoolHTTPRequestHandler, self).do_GET()