code: def obtain_check_classes(self):
          
          check_classes = set()
          for path in self.paths:
              for root, _, files in os.walk(path):
                  for fi in files:
                      if not fi.endswith(".py"):
                          continue
                      path = os.path.join(root, fi)
                      check_classes = check_classes.union(set(
                          load_check_classes_from_file(path)))
          return list(check_classes)
docs: find children of AbstractCheck class and return them as a list