add proxy for the first part and try to develop the second part

Webcal-python/venv/lib/python3.11/site-packages/attr/exceptions.pyi

@@ -0,0 +1,17 @@
+from typing import Any
+
+class FrozenError(AttributeError):
+    msg: str = ...
+
+class FrozenInstanceError(FrozenError): ...
+class FrozenAttributeError(FrozenError): ...
+class AttrsAttributeNotFoundError(ValueError): ...
+class NotAnAttrsClassError(ValueError): ...
+class DefaultAlreadySetError(RuntimeError): ...
+class UnannotatedAttributeError(RuntimeError): ...
+class PythonTooOldError(RuntimeError): ...
+
+class NotCallableError(TypeError):
+    msg: str = ...
+    value: Any = ...
+    def __init__(self, msg: str, value: Any) -> None: ...