def xml_starttag (self, name, attrs=None):
        """
        Write XML start tag.
        """
        self.write(self.indent*self.level)
        self.write(u"<%s" % xmlquote(name))
        if attrs:
            for name, value in attrs.items():
                args = (xmlquote(name), xmlquoteattr(value))
                self.write(u' %s="%s"' % args)
        self.writeln(u">")
        self.level += 1
Write XML start tag.