code: def example():
      
      client = Client(ACCOUNT_SID, AUTH_TOKEN)
  
      # Using Client Validation requires using API Keys for auth
      # First create an API key using the standard account sid, auth token client
      print('Creating new api key...')
      api_key = client.new_keys.create(friendly_name='ClientValidationApiKey')
  
      # Generate a new RSA Keypair
      print('Generating RSA key pair...')
      key_pair = rsa.generate_private_key(
          public_exponent=65537,
          key_size=2048,
          backend=default_backend()
      )
      public_key = key_pair.public_key().public_bytes(Encoding.PEM, PublicFormat.SubjectPublicKeyInfo)
      private_key = key_pair.private_bytes(Encoding.PEM, PrivateFormat.PKCS8, NoEncryption())
  
      # Register the public key with Twilio
      print('Registering public key with Twilio...')
      credential = client.accounts.credentials.public_key.create(
          public_key,
          friendly_name='ClientValidationPublicKey'
      )
  
      # Create a new ValidationClient with the keys we created
      validation_client = ValidationClient(
          ACCOUNT_SID,
          api_key.sid,
          credential.sid,
          private_key
      )
  
      # Create a REST Client using the validation_client
      client = Client(api_key.sid, api_key.secret, ACCOUNT_SID, http_client=validation_client)
  
      # Use the library as usual
      print('Trying out client validation...')
      messages = client.messages.list(limit=10)
      for m in messages:
          print('Message {}'.format(m.sid))
  
      print('Client validation works!')
docs: Example of using the ValidationClient for signed requests to Twilio.
      This is only available to enterprise customers.
  
      This will walkthrough creating an API Key, generating an RSA keypair, setting up a
      ValidationClient with these values and making requests with the client.