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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 async def encrypt( self, message: bytes, authn: bool = False, to_verkey: str = None, from_verkey: str = None) -> bytes: """ Encrypt plaintext for owner of DID, anonymously or via authenticated encryption scheme. Raise AbsentMessage for missing message, or WalletState if wallet is closed. :param message: plaintext, as bytes :param authn: whether to use authenticated encryption scheme :param to_verkey: verification key of recipient, None for anchor's own :param from_verkey: verification key of sender for authenticated encryption, None for anchor's own :return: ciphertext, as bytes """


        LOGGER.debug(
            'Wallet.encrypt >>> message: %s, authn: %s, to_verkey: %s, from_verkey: %s',
            message,
            authn,
            to_verkey,
            from_verkey)

        if not message:
            LOGGER.debug('Wallet.encrypt <!< No message to encrypt')
            raise AbsentMessage('No message to encrypt')

        if not self.handle:
            LOGGER.debug('Wallet.encrypt <!< Wallet %s is closed', self.name)
            raise WalletState('Wallet {} is closed'.format(self.name))

        if authn:
            rv = await crypto.auth_crypt(self.handle, from_verkey or self.verkey, to_verkey or self.verkey, message)
        else:
            rv = await crypto.anon_crypt(to_verkey or self.verkey, message)

        LOGGER.debug('Wallet.auth_encrypt <<< %s', rv)
        return rv