[as I created test suite and generate a test report using HTMLTestRunner (Also modified little bit by me) single test run twice.] for that code (test suite) is:
import os
import time
import unittest
from xyz.base import log
from builtins import dir
from xyz.HTMLTestRunner import HTMLTestRunner
from xyz.tests.test.test_01 import TC01
class HTestSuite(unittest.TestCase):
    log.info('Running demo test suite')
    dir = os.getcwd()
    testLoad = unittest.TestLoader()
    log.info(dir)
    test_classes_to_run =[TC01]
    suites_list = []
    for test_class in test_classes_to_run:
        suite = testLoad.loadTestsFromTestCase(test_class)
        suites_list.append(suite)
    log.info(suites_list)
    newSuite = unittest.TestSuite(suites_list)
    log.info(newSuite.countTestCases())
    timestr = time.strftime("_%Y-%m-%d_%H.%M.%S")
    
    resultFile = open(os.path.join(dir, "TestReport"+ timestr + ".html"), "w")
    runner = HTMLTestRunner(stream=resultFile, title='test report', description='Tests Execution Report') 
    runner.run(newSuite)
if __name__ == "__main__":
    unittest.main()