def write_unitth(suites, out_dir):
        """ Write UnitTH-style test reports 

        Args:
            suites (:obj:`dict`): dictionary of test suites
            out_dir (:obj:`str`): path to save UnitTH-style test reports
        """
        if not os.path.isdir(out_dir):
            os.mkdir(out_dir)

        for classname, cases in suites.items():
            doc_xml = minidom.Document()

            suite_xml = doc_xml.createElement('testsuite')
            suite_xml.setAttribute('name', classname)
            suite_xml.setAttribute('tests', str(len(cases)))
            suite_xml.setAttribute('errors', str(sum('error' in case for case in cases)))
            suite_xml.setAttribute('failures', str(sum('failure' in case for case in cases)))
            suite_xml.setAttribute('skipped', str(sum('skipped' in case for case in cases)))
            suite_xml.setAttribute('time', '{:.3f}'.format(sum(case['time'] for case in cases)))
            doc_xml.appendChild(suite_xml)

            for case in cases:
                case_xml = doc_xml.createElement('testcase')
                case_xml.setAttribute('classname', classname)
                case_xml.setAttribute('name', case['name'])
                case_xml.setAttribute('time', '{:.3f}'.format(case['time']))
                suite_xml.appendChild(case_xml)

                if 'skipped' in case:
                    skipped_xml = doc_xml.createElement('skipped')
                    skipped_xml.setAttribute('type', case['skipped']['type'])
                    skipped_xml.setAttribute('message', case['skipped']['message'])
                    case_xml.appendChild(skipped_xml)

                    skipped_text_xml = doc_xml.createCDATASection(case['skipped']['text'])
                    skipped_xml.appendChild(skipped_text_xml)

                if 'failure' in case:
                    failure_xml = doc_xml.createElement('failure')
                    failure_xml.setAttribute('type', case['failure']['type'])
                    failure_xml.setAttribute('message', case['failure']['message'])
                    case_xml.appendChild(failure_xml)

                    failure_text_xml = doc_xml.createCDATASection(case['failure']['text'])
                    failure_xml.appendChild(failure_text_xml)

                if 'error' in case:
                    error_xml = doc_xml.createElement('error')
                    error_xml.setAttribute('type', case['error']['type'])
                    error_xml.setAttribute('message', case['error']['message'])
                    case_xml.appendChild(error_xml)

                    error_text_xml = doc_xml.createCDATASection(case['error']['text'])
                    error_xml.appendChild(error_text_xml)

            with open(os.path.join(out_dir, '{}.xml'.format(classname)), 'w') as output:
                doc_xml.writexml(output, encoding='utf-8', addindent='', newl="")
            doc_xml.unlink()
Write UnitTH-style test reports 

        Args:
            suites (:obj:`dict`): dictionary of test suites
            out_dir (:obj:`str`): path to save UnitTH-style test reports