docs: def list_bootstraps(cls):
          '''Find all the available bootstraps and return them.'''
          forbidden_dirs = ('__pycache__', 'common')
          bootstraps_dir = join(dirname(__file__), 'bootstraps')
          for name in listdir(bootstraps_dir):
              if name in forbidden_dirs:
                  continue
              filen = join(bootstraps_dir, name)
              if isdir(filen):
                  yield name