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