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

        :param width: If given, the chart's width will be set to this.

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

        :param width: If given, the chart's width will be set to this."""

        if width is None:
            return self._width
        else:
            if not is_numeric(width):
                raise TypeError("width must be numeric, not '%s'" % str(width))
            self._width = width