code: def encrypt(self, plaintext):
          
  
          # Encrpyt message key.
          msg_key = random_letters(3)
          while msg_key == self.grundstellung:
              msg_key = random_letters(3)
          self.machine.set_display(self.grundstellung)
          enc_key = self.machine.process_text(msg_key)
  
          # Encrpyt message.
          self.machine.set_display(msg_key)
          ciphertext = self.machine.process_text(plaintext)
  
          # Encode message with keys.
          return "{enc_key}{ciphertext}{grundstellung}".format(
              enc_key=enc_key,
              ciphertext=ciphertext,
              grundstellung=self.grundstellung
          )
docs: Have the operator encrypt a message.