input: def create_virtual_assistant(project_id: str, session_id: str) -> None:
      """ Create a virtual assistant using Python and Dialogflow to answer a basic set of questions.
      The assistant will continuously prompt the user for input, send the input to Dialogflow,
      and print the response from Dialogflow.
      >>> create_virtual_assistant('project-id', 'session-id')
      User: Hello
      Assistant: Hi there! How can I help you today?
      """
output:     import dialogflow_v2 as dialogflow
      import os
  
      os.environ["GOOGLE_APPLICATION_CREDENTIALS"] = "path_to_your_credentials_file.json"
  
      session_client = dialogflow.SessionsClient()
      session = session_client.session_path(project_id, session_id)
  
      while True:
          user_input = input("User: ")
          text_input = dialogflow.types.TextInput(text=user_input, language_code='en')
          query_input = dialogflow.types.QueryInput(text=text_input)
          response = session_client.detect_intent(session=session, query_input=query_input)
          print(f"Assistant: {response.query_result.fulfillment_text}")