input: from typing import List
  
  def clean_html_tags(str: str) -> str:
      """ Clean a string of HTML tags
      >>> clean_html_tags("<p>This is a <b>test</b> string</p>")
      'This is a test string'
      >>> clean_html_tags("<div><a href='link'>Click here</a></div>")
      'Click here'
      """
output:     import re
      cleaned_str = re.sub(r'<[^>]+>', '', str)
      return cleaned_str