def pre_validation(self, config, key_name):

        if config.get(key_name) is None or self.moved_to is None:
            return

        warning = ('The configuration option {0} has been deprecated and will '
                   'be removed in a future release of MkDocs.')
        self.warnings.append(warning)

        if '.' not in self.moved_to:
            target = config
            target_key = self.moved_to
        else:
            move_to, target_key = self.moved_to.rsplit('.', 1)

            target = config
            for key in move_to.split('.'):
                target = target.setdefault(key, {})

                if not isinstance(target, dict):
                    # We can't move it for the user
                    return

        target[target_key] = config.pop(key_name)
dataset/ETHPy150Open mkdocs/mkdocs/mkdocs/config/config_options.py/Deprecated.pre_validation/original