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

        Returns:
            (bool | None): Value of key, if defined

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

        Returns:
            (bool | None): Value of key, if defined

        """
        value = self.get_str(key)
        if value is not None:
            return to_boolean(value)

        return default