input: Write a function to crawl a website for a specific type of data (phone numbers). The function should accept the website URL as an argument and return a list of phone numbers found on that webpage. If the webpage content is not accessible, the function should return an empty list.
  assert crawl_website_for_phone_numbers('http://www.example.com')==['800-123-4567', '888-999-0000']
  assert crawl_website_for_phone_numbers('https://nonexistentwebsite.com')==[]
  assert crawl_website_for_phone_numbers('http://anothersite.com')==[]
  assert crawl_website_for_phone_numbers('http://sitewithphonenumbers.com')==['111-222-3333', '444-555-6666']
  assert crawl_website_for_phone_numbers('http://sitewithoutphonenumbers.com')==[]
output: import re
  import requests
  
  def crawl_website_for_phone_numbers(url):
      try:
          response = requests.get(url)
          response.raise_for_status()
          content = response.text
          phone_numbers = re.findall(r'\b\d{3}-\d{3}-\d{4}\b', content)
          return phone_numbers
      except:
          return []