Writes an Xunit-formatted XML file

        The file includes a report of test errors and failures.

def report(self, stream):
        """Writes an Xunit-formatted XML file

        The file includes a report of test errors and failures.

        """
        from collections import OrderedDict
        self.stats['total'] = sum(self.stats.values())
        for group in self.report_data.values():
            group.stats['total'] = sum(group.stats.values())
        self.report_file.write(self.jinja.get_template('report.html').render(
            report=OrderedDict(sorted(self.report_data.items())),
            stats=self.stats,
        ))
        self.report_file.close()
        if self.config.verbosity > 1:
            stream.writeln("-" * 70)
            stream.writeln("HTML: %s" % self.report_file.name)