Add json() method for parsing request

slow/slow.py

@@ -3,6 +3,7 @@ import http.client
 import json
 import re
 import urllib.parse
+from json.decoder import JSONDecodeError
 from pathlib import Path
 from typing import Any, Awaitable, Callable, Optional
 
@@ -57,6 +58,11 @@ class Request:
             }
         )
 
+    def json(self) -> dict | None:
+        try:
+            return json.loads(self.body)
+        except JSONDecodeError:
+            return None
 
 async def _default_404_route(request: Request):
     return "HTTP/1.1 404 Not Found\r\nContent-Type: text/html\r\n\r\n404 Not Found contact admin".encode(