input: from typing import List
  
  def remove_unwanted_elements(text: str) -> List[str]:
      """ Remove all punctuation, special characters, and stopwords from a given tweet.
      >>> remove_unwanted_elements("I'm so excited to be going to the #MuseumTour! #BigDay #travel")
      ['excited', 'going', 'MuseumTour', 'BigDay', 'travel']
      """
output:     import string
      from nltk.corpus import stopwords
      from nltk.tokenize import word_tokenize
  
      # Tokenize the text
      tokens = word_tokenize(text)
  
      # Remove punctuation and convert to lowercase
      tokens = [word.lower() for word in tokens if word.isalnum()]
  
      # Remove stopwords
      stop_words = set(stopwords.words('english'))
      filtered_tokens = [word for word in tokens if word not in stop_words]
  
      return filtered_tokens