input: Write a Python function to simulate a chatbot with predefined responses.
  assert chatbot("Hi there!") in ["Hello there!", "Howdy!", "Hi 👋"]
  assert chatbot("How are you doing?") in ["I'm doing great!", "Doing well!", "Never better 🤩"]
  assert chatbot("Goodbye!") in ["Goodbye!", "See you later!", "Bye bye"]
  assert chatbot("What is your name?") == "Sorry, I don't understand 🤔"
output: def chatbot(message):
      responses = {
          "Hi there!": ["Hello there!", "Howdy!", "Hi 👋"],
          "How are you doing?": ["I'm doing great!", "Doing well!", "Never better 🤩"],
          "Goodbye!": ["Goodbye!", "See you later!", "Bye bye"]
      }
      if message in responses:
          return responses[message][0]
      else:
          return "Sorry, I don't understand 🤔"