input: from typing import List
  
  
  def clean_tweet(tweet: str) -> List[str]:
      """ Removes all punctuation, special characters, and stopwords from a given tweet.
      >>> clean_tweet("I'm so excited to be going to the #MuseumTour! #BigDay #travel")
      ['excited', 'going', 'MuseumTour', 'BigDay', 'travel']
      """
output:     import re
      from nltk.corpus import stopwords
  
      # Remove punctuation and special characters
      tweet = re.sub(r'[^\w\s]', '', tweet)
  
      # Convert to lowercase and split into words
      words = tweet.lower().split()
  
      # Remove stopwords
      stop_words = set(stopwords.words('english'))
      cleaned_words = [word for word in words if word not in stop_words]
  
      return cleaned_words