docs: def _tls_auth_encrypt(self, s):
          """
          Return the TLSCiphertext.encrypted_record for AEAD ciphers.
          """
          wcs = self.tls_session.wcs
          write_seq_num = struct.pack("!Q", wcs.seq_num)
          wcs.seq_num += 1
          return wcs.cipher.auth_encrypt(s, b"", write_seq_num)