input: 
  def virtual_assistant_dialogflow(project_id: str, session_id: str) -> None:
      """Set up a virtual assistant using Dialogflow to answer a basic set of questions.
      The assistant will continuously take user input and respond with a fulfillment text.
      >>> virtual_assistant_dialogflow('project-id', 'session-id')
      User: Hello
      Assistant: Hi there! How can I assist you today?
      """
      import dialogflow_v2 as dialogflow
      import requests
  
      session_client = dialogflow.SessionsClient()
      session = session_client.session_path(project_id, session_id)
  
      while True:
          text = input('User: ')
          text_input = dialogflow.types.TextInput(text=text, language_code='en-US')
          query_input = dialogflow.types.QueryInput(text=text_input)
          response = session_client.detect_intent(session=session, query_input=query_input)
  
          print('Assistant:', response.query_result.fulfillment_text)
  
output:     if text.lower() in ['exit', 'quit', 'bye']:
          print('Assistant: Goodbye!')
          break