code: def _readall(self):
          
          # First priority -- read all default configs
          config_path = os.path.dirname(__file__)
          config_defaults = [os.path.join(dirpath, f)
                             for dirpath, dirnames, files in os.walk(config_path)
                             for f in fnmatch.filter(files, 'default.cfg')]
  
          # Second priority -- read the user overrides
          user_config = os.path.expanduser('~/.aftrc')
  
          # Third priority -- read the environment variable overrides
          override_filenames = []
          if TEST_RUN_SETTING_CONFIG in os.environ:
              for test_config in os.environ[TEST_RUN_SETTING_CONFIG].split(','):
                  if os.path.exists(test_config):             #is this a file path
                     override_filenames.append(test_config)
                  elif "." in test_config and not test_config.endswith('.cfg'):                    #else it might be in xxxx.yyyy format
                      config_parts = test_config.split('.')
                      config_parts[-1]+='.cfg' #add file ext to last part, which should be file
                      filename = os.path.join(config_path, *config_parts)
                      override_filenames.append(filename)
                  else:                                       #else unknown, might throw exception here
                      pass
  
  
          all_configs = config_defaults + [user_config] + override_filenames
          return self.parser.read(all_configs)
docs: Read configs from all available configs. It will read files in the following order:
  
              1.) Read all default settings:
  
                  These are located under: `<project_root>/config/*/default.cfg`
  
              2.) Read the user's config settings:
  
                  This is located on the path: `~/.aftrc`
  
              3.) Read all config files specified by the config string in the environment variable TEST_RUN_SETTING_CONFIG
  
                  A config string such as "browser.headless,scripts.no_ssh" will read paths:
  
                      `<project_root>/config/browser/headless.cfg`
                      `<project_root>/config/scripts/no_ssh.cfg`
  
                  OR a config string such as "<project_root>/config/browser/headless.cfg" will load that path directly