from http.server import ThreadingHTTPServer, BaseHTTPRequestHandler
import time
class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        print('REQUEST_STARTED', flush=True)
        time.sleep(240)
        self.send_response(200)
        self.end_headers()
        try: self.wfile.write(b'complete')
        except BrokenPipeError: pass
ThreadingHTTPServer(('127.0.0.1',18787),Handler).serve_forever()