input: Write a function to create a simple chatbot using Python and Dialogflow, which can answer questions about the current days of the week. The function should involve setting up a Flask application with an endpoint that can handle GET and POST requests. It should leverage Dialogflow's intent detection capabilities to respond to user queries about the days of the week. If a session_id is not provided, the function should automatically generate one.
  from flask import Flask
  from flask_restful import Resource, Api
  from dialogflow import detect_intent_texts
  
  app = Flask(__name__)
  api = Api(app)
  
  
  @app.route('/', methods=['GET', 'POST'])
  def detect_intent_text():
      IF session_id NOT present
          PLEASE create session_id
      request = detect_intent_texts(session_id, text)
      response = request.fulfillment_text
      return response
  
  
  if __name__ == '__main__':
      app.run()
  assert detect_intent_text('Hello', session_id='123')=='What day is it today?'
  assert detect_intent_text('What day is it today?', session_id='456')=='Today is Monday.'
  assert detect_intent_text('Is today Monday?', session_id='789')=='Yes, today is Monday.'
output: 
  @app.route('/', methods=['GET', 'POST'])
  def detect_intent_text():
      from uuid import uuid4
      session_id = request.args.get('session_id') or str(uuid4())
      text = request.args.get('text')
      request = detect_intent_texts(session_id, text)
      response = request.fulfillment_text
      return response
  