code: def _raw_read(self):
          
  
          data = self._raw_bytes
          try:
              data += self._socket.recv(8192)
          except (socket_.error):
              pass
          output = data
          written = libssl.BIO_write(self._rbio, data, len(data))
          self._raw_bytes = data[written:]
          return output
docs: Reads data from the socket and writes it to the memory bio
          used by libssl to decrypt the data. Returns the unencrypted
          data for the purpose of debugging handshakes.
  
          :return:
              A byte string of ciphertext from the socket. Used for
              debugging the handshake only.