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 parse the webpage to find HTML elements using tags and attributes, extract the required data, and convert it into the desired format for storage.
  
  def extract_data(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')
      
      # Example: Find all 'a' tags and extract URLs in the 'href' attribute
      links = soup.find_all('a')
      urls = [link.get('href') for link in links]
      
      return urls
  
  assert extract_data("<url_of_webpage>")==["<url_1>", "<url_2>", "<url_3>"]
  assert extract_data("<another_url_of_webpage>")==["<url_1>", "<url_2>", "<url_3>"]
  assert extract_data("<empty_webpage_url>")==[]
  assert extract_data("<wrong_url>")==AssertionError
output: def extract_data(url):
      import requests
      from bs4 import BeautifulSoup
      
      webpage = requests.get(url)
      soup = BeautifulSoup(webpage.content, 'html.parser')
      links = soup.find_all('a')
      urls = [link.get('href') for link in links]
      
      return urls