input: Write a function to convert a given sentence into speech using Python. The function should initialize a Text-to-Speech engine, say the sentence, and run the engine to wait for the speech to complete. If the input sentence is empty, the function should simply return without producing any output.
  def text_to_speech(sentence):
      if not sentence:
          return
      engine = pyttsx3.init()
      engine.say(sentence)
      engine.runAndWait()
  
  assert text_to_speech("Hello, this is a simple sentence") == None
  assert text_to_speech("") == None
  assert text_to_speech("Testing the text-to-speech function") == None
output: def text_to_speech(sentence):
      if not sentence:
          return
      engine = pyttsx3.init()
      engine.say(sentence)
      engine.runAndWait()