code: def ephemeral(cls):
          
          private_key = nacl.public.PrivateKey(os.urandom(32))
          return cls(private_key.public_key, private_key)
docs: Creates a new ephemeral key constructed using a raw 32-byte string from urandom.
          Ephemeral keys are used once for each encryption task and are then discarded;
          they are not intended for long-term or repeat use.