input: Write a function to scrape a webpage and collect all the links from it. Return a list of all the href values found in the 'a' tags. If no links are found, return an empty list.
  assert scrape_webpage("http://www.example.com/")==['http://www.example.com/page1', 'http://www.example.com/page2']
output: import requests
  from bs4 import BeautifulSoup
  
  def scrape_webpage(url):
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
      links = [a['href'] for a in soup.find_all('a', href=True)]
      return links