def adjust_validator_signatures(self) -> None:
        """When we decorate a function `f` with `pydantic.validator(...), mypy sees
        `f` as a regular method taking a `self` instance, even though pydantic
        internally wraps `f` with `classmethod` if necessary.

        Teach mypy this by marking any function whose outermost decorator is a
        `validator()` call as a classmethod.
        """
        for name, sym in self._ctx.cls.info.names.items():
            if isinstance(sym.node, Decorator):
                first_dec = sym.node.original_decorators[0]
                if (
                    isinstance(first_dec, CallExpr)
                    and isinstance(first_dec.callee, NameExpr)
                    and first_dec.callee.fullname == f'{_NAMESPACE}.class_validators.validator'
                ):
                    sym.node.func.is_class = True
When we decorate a function `f` with `pydantic.validator(...), mypy sees
        `f` as a regular method taking a `self` instance, even though pydantic
        internally wraps `f` with `classmethod` if necessary.

        Teach mypy this by marking any function whose outermost decorator is a
        `validator()` call as a classmethod.
        
pydantic/v1/mypy.py