input: Write a python function to fetch the HTML content of a given URL and return it as a string.
  assert fetch_html_content("https://www.example.com") == requests.get("https://www.example.com").content
  assert fetch_html_content("https://www.google.com") == requests.get("https://www.google.com").content
output: import requests
  
  def fetch_html_content(url):
      response = requests.get(url)
      return response.content