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 there are fewer than 5 words, it should return all available words. The function should return a list of strings.
  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("hello")==['hello', 'hello world', 'hell', 'hellfire', 'hello there']
  assert autocomplete("python")==['python', 'pythonic', 'python programming', 'pythonista', 'python code']
  assert autocomplete("testing")==['testing', 'test', 'tester', 'test suite', 'test environment']
  assert autocomplete("abc")==[]
  assert autocomplete("")==[]
output: 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]