async def update_vars_internal(self, vars: dict[str, Any]) -> None:
        """Apply updates to fully qualified state vars.

        The keys in `vars` should be in the form of `{state.get_full_name()}.{var_name}`,
        and each value will be set on the appropriate substate instance.

        This function is primarily used to apply cookie and local storage
        updates from the frontend to the appropriate substate.

        Args:
            vars: The fully qualified vars and values to update.
        """
        for var, value in vars.items():
            state_name, _, var_name = var.rpartition(".")
            var_state_cls = State.get_class_substate(state_name)
            if var_state_cls._is_client_storage(var_name):
                var_state = await self.get_state(var_state_cls)
                setattr(var_state, var_name, value)
Apply updates to fully qualified state vars.

        The keys in `vars` should be in the form of `{state.get_full_name()}.{var_name}`,
        and each value will be set on the appropriate substate instance.

        This function is primarily used to apply cookie and local storage
        updates from the frontend to the appropriate substate.

        Args:
            vars: The fully qualified vars and values to update.
        
reflex/state.py