input: Write a function to create a web scraper that extracts specific data from a given website using the Python package BeautifulSoup. The function should utilize BeautifulSoup to parse webpages and extract the required data, which can then be converted into the desired format and stored.
  
  Create web_scraper(url):
      import requests
      from bs4 import BeautifulSoup
  
      # Get the web page
      webpage = requests.get(url)
  
      # Parse the web page
      soup = BeautifulSoup(webpage.content, 'html.parser')
  
      # Find all 'a' tags
      links = soup.find_all('a')
  
      # Extract the URLs in the 'href' attribute
      return [link.get('href') for link in links]
  
  assert web_scraper("https://example.com")==["https://example.com/link1", "https://example.com/link2"]
  assert web_scraper("")==[]
  assert web_scraper("https://invalidurl.com")==[]
output: def web_scraper(url):
      import requests
      from bs4 import BeautifulSoup
  
      try:
          webpage = requests.get(url)
          soup = BeautifulSoup(webpage.content, 'html.parser')
          links = soup.find_all('a')
          return [link.get('href') for link in links]
      except:
          return []