How to use the pysodium.crypto_box_keypair function in pysodium

def test_crypto_box_open_afternm(self):
        m = b"howdy"
        pk, sk = pysodium.crypto_box_keypair()
        k = pysodium.crypto_box_beforenm(pk, sk)
        n = pysodium.randombytes(pysodium.crypto_box_NONCEBYTES)
        c = pysodium.crypto_box_afternm(m, n, k)
        self.assertEqual(c, c)
        plaintext = pysodium.crypto_box_open_afternm(c, n, k)
        self.assertEqual(m, plaintext)

def initialize():
    """
    Create a ~/.zkm directory with a config file inside.

    The config file will hold our public key, secret key, and since value.
    """
    if os.path.exists(ZKMDIR) is False:
        print('[+] Creating ZKM configuration directory.')
        os.mkdir(ZKMDIR, 0o750)

        print('[+] Creating new keypair.')
        our_public, our_secret = pysodium.crypto_box_keypair()

        print('[+] Creating configuration file.')
        config = {b'public': base64.b64encode(our_public),
                  b'secret': base64.b64encode(our_secret),
                  b'since': b'1',
                  b'channel': b'default'}

        save_data(CONFIG, config)
        os.chmod(CONFIG, 0o600)

        print('[+] Creating contacts file.')
        save_data(CONTACT, {})
        os.chmod(CONTACT, 0o600)

    else:
        print('[-] ZKM configuration directory already exists.')

def create(self):
        self.created = datetime.datetime.utcnow()
        self.valid = datetime.datetime.utcnow() + datetime.timedelta(days=365)
        self.mp, self.ms = nacl.crypto_sign_keypair()
        self.sp, self.ss = nacl.crypto_sign_keypair()
        self.cp, self.cs = nacl.crypto_box_keypair()
        self.save()

def create(self):
        self.created = datetime.datetime.utcnow()
        self.valid = datetime.datetime.utcnow() + datetime.timedelta(days=365)
        self.mp, self.ms = nacl.crypto_sign_keypair()
        self.sp, self.ss = nacl.crypto_sign_keypair()
        self.cp, self.cs = nacl.crypto_box_keypair()
        self.save()

def register(team_name, countries):
    team_name = to_unicode(team_name)

    log.info('updating subrepo')
    SubRepo.pull()

    log.info('registering new team: %s' % team_name)
    team = Team(name=team_name)

    if team.exists():
        log.fail('team is already registered')
        return False

    log.info('generating encryption keypair')
    crypt_pk, crypt_sk = pysodium.crypto_box_keypair()

    log.info('generating signature keypair')
    sign_pk, sign_sk = pysodium.crypto_sign_keypair()

    team.update({'countries': countries,
                 'crypt_pk': crypt_pk,
                 'sign_pk': sign_pk})
    team.validate()
    team.save()

    SubRepo.push(commit_message='Register team %s' % team_name)
    log.success('team %s added successfully' % team_name)

    write_team_secrets(team.id, crypt_sk, sign_sk)

    return True