fix: use typing_extensions Self for py310

Author: Wondr-design

pyproject.toml

@@ -13,6 +13,7 @@ dependencies = [
   "pydantic>=2.11.3",
   "protobuf>=5.29.5",
   "google-api-core>=1.26.0",
+  "typing-extensions>=4.0.0",
 ]
 
 classifiers = [

src/a2a/utils/telemetry.py

@@ -62,10 +62,13 @@ def internal_method(self):
 from typing import TYPE_CHECKING, Any
 
 
-try:
-    from typing import Self
-except ImportError:  # pragma: no cover - for Python < 3.11
+if TYPE_CHECKING:
     from typing_extensions import Self
+else:
+    try:
+        from typing import Self
+    except ImportError:  # pragma: no cover - for Python < 3.11
+        from typing_extensions import Self
 
 
 if TYPE_CHECKING: