'Get the URL for our graph.
Args:
use_html_entities: If True, reserved HTML characters (&, <, >, ") in the
URL are replaced with HTML entities (&amp;, &lt;, etc.). Default is False.'

def Url(self, width, height, use_html_entities=False):

    self._width = width
    self._height = height
    params = self._Params(self.chart)
    return util.EncodeUrl(self.url_base, params, self.escape_url, use_html_entities)
