Args:
            key (str | unicode): Key to lookup
            default (float | None): Default to use if key is not configured
            minimum (float | None): If specified, result can't be below this minimum
            maximum (float | None): If specified, result can't be above this maximum

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

def get_float(self, key, default=None, minimum=None, maximum=None):
        """
        Args:
            key (str | unicode): Key to lookup
            default (float | None): Default to use if key is not configured
            minimum (float | None): If specified, result can't be below this minimum
            maximum (float | None): If specified, result can't be above this maximum

        Returns:
            (float | None): Value of key, if defined
        """
        return to_number(float, self.get_str(key), default=default, minimum=minimum, maximum=maximum)