input: Write a python function to get the title and author of an Amazon book page using BeautifulSoup.
  assert get_book_details('https://www.amazon.com/Cup-Stars-Novel-Alex-Awards-ebook/dp/B07PWNWS3G') == ('A Cup of Stars', 'Elizabeth Macneal')
  assert get_book_details('https://www.amazon.com/Life-Will-Dark-Novel/dp/B07KY7P1SR') == ('Life Will Be the Death of Me', 'Chelsea Handler')
output: def get_book_details(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      
      title = soup.find(id='productTitle').get_text(strip=True)
      author = soup.find('a', class_='contributorNameID').get_text(strip=True)
      
      return title, author