input: Write a function to scrape a given website and return its HTML content. If the website URL is invalid or the request fails, the function should return an appropriate error message.
  def scrape_website(url: str) -> str:
      try:
          page = requests.get(url)
          if page.status_code == 200:
              soup = BeautifulSoup(page.text, 'html.parser')
              return soup.prettify()
          else:
              return f"Error: Unable to fetch the webpage. Status code: {page.status_code}"
      except requests.RequestException as e:
          return f"Error: {e}"
  
  assert scrape_website('https://www.example.com')==<expected HTML content>
  assert scrape_website('invalidurl')=="Error: Invalid URL 'invalidurl': No schema supplied. Perhaps you meant http://invalidurl?"
  assert scrape_website('https://nonexistentdomain12345.com')=="Error: Unable to fetch the webpage. Status code: 404"
output: def scrape_website(url: str) -> str:
      try:
          page = requests.get(url)
          if page.status_code == 200:
              soup = BeautifulSoup(page.text, 'html.parser')
              return soup.prettify()
          else:
              return f"Error: Unable to fetch the webpage. Status code: {page.status_code}"
      except requests.RequestException as e:
          return f"Error: {e}"