input: Write a python function to get and parse the content of a webpage using BeautifulSoup.
  assert parse_webpage('http://example.org/') is not None
  assert isinstance(parse_webpage('http://example.org/'), BeautifulSoup)
output: def parse_webpage(url):
      import requests
      from bs4 import BeautifulSoup
  
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      return soup