input: Write a python function to extract titles, authors, and contents from a list of articles using BeautifulSoup. 
  assert extract_articles('https://example.com/articles')==[
      {'title': 'Title 1', 'author': 'Author 1', 'content': 'Content 1'},
      {'title': 'Title 2', 'author': 'Author 2', 'content': 'Content 2'}
  ]
  assert extract_articles('https://example.com/other-articles')==[
      {'title': 'Title A', 'author': 'Author A', 'content': 'Content A'},
      {'title': 'Title B', 'author': 'Author B', 'content': 'Content B'}
  ]
output: def extract_articles(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      
      articles = []
      for article in soup.find_all('article'):
          title = article.find('h1', class_='title').text
          author = article.find('span', class_='author').text
          content = article.find('div', class_='content').text
          
          articles.append({'title': title, 'author': author, 'content': content})
      
      return articles