docs: def _load_script(self, filename: str) -> Script:
          """Load a Lua script.
  
          Read the Lua script file to generate its Script object. If the script
          starts with a magic string, add it to the list of scripts requiring an
          idempotency token to execute.
          """
          with open(path.join(here, 'redis_scripts', filename), mode='rb') as f:
              script_data = f.read()
          rv = self._r.register_script(script_data)
          if script_data.startswith(b'-- idempotency protected script'):
              self._idempotency_protected_scripts.append(rv)
          return rv