input: Write a function to create an autocomplete system that predicts words based on the input text. The function should generate word candidates, filter them, rank them, and return the top 5 predicted words. If the input text is empty or there are fewer than 5 candidates, return the available candidates.
  def autocomplete(input_text):
      # Generate the word candidates
      word_candidates = generate_candidates(input_text)
      # Filter the word candidates 
      filtered_words = filter_candidates(word_candidates)
      # Rank the words and return the top 5 
      sorted_words = rank_words(filtered_words)
      return sorted_words[:5]
  assert autocomplete("pro")==["program", "produce", "progress", "project", "proposal"]
  assert autocomplete("te")==["test", "technology", "temperature", "telephone", "telemetry"]
  assert autocomplete("")==["the", "of", "and", "to", "in"]
  assert autocomplete("missing")==["missing", "missile", "mission", "mistake", "missed"]
  assert autocomplete("unique")==["unique", "uniquely", "uniqueness", "unified", "unisex"]
output: def autocomplete(input_text):
      word_candidates = generate_candidates(input_text)
      filtered_words = filter_candidates(word_candidates)
      sorted_words = rank_words(filtered_words)
      return sorted_words[:5]