input: def scrape_web_data(url: str, tags_and_attributes: dict) -> dict:
      """Create a web scraper that extracts specific data from a given website.
      The web scraper should utilize the Python package BeautifulSoup to parse webpages and extract the required data.
      BeautifulSoup will allow us to find HTML elements on the webpage using tags and attributes.
      Once the data is found, it can be converted into the desired format and stored.
      
      Example:
      >>> scrape_web_data("<url_of_webpage>", {'a': 'href'})
      {'links': ['link1', 'link2', 'link3']}
      """
output:     from bs4 import BeautifulSoup
      import requests
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
  
      result = {}
      for tag, attribute in tags_and_attributes.items():
          elements = soup.find_all(tag)
          result[attribute] = [element.get(attribute) for element in elements if element.get(attribute)]
  
      return result