a2a-source-edit: write agent.py

agent.py

@@ -4,7 +4,7 @@ import csv
 import json
 import re
 import time
-from dataclasses import asdict, dataclass
+from dataclasses import asdict, dataclass, field
 from typing import Any, Dict, List, Literal, Optional, Tuple
 from urllib.parse import urljoin, urlparse
 from urllib import robotparser