Returns or sets (if a value is provided) the chart's title.

        :param str title: If given, the chart's title will be set to this.
        :rtype: ``str``

def title(self, title=None):
        """Returns or sets (if a value is provided) the chart's title.

        :param str title: If given, the chart's title will be set to this.
        :rtype: ``str``"""

        if title is None:
            return self._title
        else:
            if not isinstance(title, str):
                raise TypeError("title must be str, not '%s'" % str(title))
            self._title = title