code: def encrypt(self, plaintext, encoder=encoding.RawEncoder):
          
  
          ciphertext = nacl.bindings.crypto_box_seal(
              plaintext,
              self._public_key
          )
  
          encoded_ciphertext = encoder.encode(ciphertext)
  
          return encoded_ciphertext
docs: Encrypts the plaintext message using a random-generated ephemeral
          keypair and returns a "composed ciphertext", containing both
          the public part of the keypair and the ciphertext proper,
          encoded with the encoder.
  
          The private part of the ephemeral key-pair will be scrubbed before
          returning the ciphertext, therefore, the sender will not be able to
          decrypt the generated ciphertext.
  
          :param plaintext: [:class:`bytes`] The plaintext message to encrypt
          :param encoder: The encoder to use to encode the ciphertext
          :return bytes: encoded ciphertext