input: Write a python function to extract all anchor tags and their href attributes from a given URL.
  assert extract_anchors("https://www.example.com") == [('Example Domain', 'https://www.iana.org/domains/example')]
  assert extract_anchors("https://www.wikipedia.org") == [('English', 'https://en.wikipedia.org/'), ('Español', 'https://es.wikipedia.org/'), ('Deutsch', 'https://de.wikipedia.org/')]
  assert extract_anchors("https://www.python.org") == [('Python', 'https://www.python.org/'), ('Downloads', 'https://www.python.org/downloads/')]
output: def extract_anchors(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
  
      anchors = []
      for a in soup.find_all('a', href=True):
          text = a.get_text(strip=True)
          href = a['href']
          if text and href:
              anchors.append((text, href))
  
      return anchors