docs: def resolve_name(name, package):
      """Resolve a relative module name to an absolute one."""
      if not name.startswith('.'):
          return name
      elif not package:
          raise ValueError('{!r} is not a relative name '
                           '(no leading dot)'.format(name))
      level = 0
      for character in name:
          if character != '.':
              break
          level += 1
      return _resolve_name(name[level:], package, level)