Args:
            key (str | unicode): Key to lookup
            default (str | unicode | dict | list | None): Default to use if key is not configured

        Returns:
            (dict | list | str | int | None): Deserialized json, if any

def get_json(self, key, default=None):
        """
        Args:
            key (str | unicode): Key to lookup
            default (str | unicode | dict | list | None): Default to use if key is not configured

        Returns:
            (dict | list | str | int | None): Deserialized json, if any
        """
        value = self.get_str(key)
        if value is not None:
            value = from_json(value)
            if value is not None:
                return value

        if isinstance(default, (dict, list)):
            return default

        return from_json(default)