input: def chatbot_using_state_diagrams() -> None:
      """Create a simple chatbot using Python and state diagrams. The chatbot will have multiple states with specific messages and replies, and it will transition between these states based on user input. The chatbot will end the conversation when it reaches a terminal state (a state with no replies).
      
      >>> chatbot = chatbot_using_state_diagrams()
      Hello! How can I help you?
      >> I need some advice
      Sure, what kind of advice do you need?
      >> Career advice
      It is always a good idea to research the field you are interested in and creating a plan to learn the skills that are required. Make sure to contact professionals in the field to understand their experience.
      Goodbye!
      =========================
      Conversation:
      Hello! How can I help you?
      I need some advice
      Sure, what kind of advice do you need?
      Career advice
      It is always a good idea to research the field you are interested in and creating a plan to learn the skills that are required. Make sure to contact professionals in the field to understand their experience.
      """
output:     states = {
          "start": {
              "message": "Hello! How can I help you?",
              "replies": {
                  "I need some advice": "advice"
              }
          },
          "advice": {
              "message": "Sure, what kind of advice do you need?",
              "replies": {
                  "Career advice": "career_advice"
              }
          },
          "career_advice": {
              "message": "It is always a good idea to research the field you are interested in and creating a plan to learn the skills that are required. Make sure to contact professionals in the field to understand their experience.",
              "replies": {}
          }
      }
  
      current_state = "start"
  
      while states[current_state]["replies"]:
          print(states[current_state]["message"])
          user_input = input(">> ")
          if user_input in states[current_state]["replies"]:
              current_state = states[current_state]["replies"][user_input]
          else:
              print("Sorry, I didn't understand that.")
  
      print(states[current_state]["message"])
      print("Goodbye!")