'Yields a string of HTML with a <div id="graph"> containing a <script type="text/canvas">.
The <div id="graph"> wrapper is required as a container for the node labels.'

@property
def canvas(self):

    s = [('<div    id="%s"    style="width:%spx;    height:%spx;">\n' % (self.id, self.width, self.height)), ' DCTB <script    type="text/canvas">\n', (' DCTB  DCTB %s\n' % self.script.replace('\n', '\n DCTB  DCTB ')), ' DCTB </script>\n', '</div>']
    return ''.join(s)
