input: Write a python function to fetch meta tags from a given URL and return them as a dictionary.
  assert fetch_meta_tags("http://www.example.com") == {'description': 'Example Domain', 'keywords': 'example, domain'}
  assert fetch_meta_tags("http://www.test.com") == {'author': 'Test', 'viewport': 'width=device-width, initial-scale=1.0'}
  assert fetch_meta_tags("http://www.sample.com") == {'charset': 'UTF-8', 'robots': 'index, follow'}
output: def fetch_meta_tags(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
  
      meta_tags = {}
      for meta in soup.find_all('meta'):
          if 'name' in meta.attrs and 'content' in meta.attrs:
              meta_tags[meta.attrs['name']] = meta.attrs['content']
          elif 'property' in meta.attrs and 'content' in meta.attrs:
              meta_tags[meta.attrs['property']] = meta.attrs['content']
  
      return meta_tags