input: Write a python function to get all the links from a webpage.
  assert get_all_links('http://example.com/') == ['http://example.com/link1', 'http://example.com/link2']
  assert get_all_links('http://anotherexample.com/') == ['http://anotherexample.com/home', 'http://anotherexample.com/about']
  assert get_all_links('http://yetanotherexample.com/') == ['http://yetanotherexample.com/contact', 'http://yetanotherexample.com/blog']
output: def get_all_links(url):
      import requests
      from bs4 import BeautifulSoup
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      links = [a['href'] for a in soup.find_all('a', href=True)]
      return links