code: def _track(self, class_name):
          
          if self._test_cases.get(class_name) is None:
              if self.streaming and self.header:
                  self._write_test_case_header(class_name, self.stream)
  
              self._test_cases[class_name] = []
              if self.combined:
                  self.combined_test_cases_seen.append(class_name)
docs: Keep track of which test cases have executed.