input: Write a python function to fetch the first paragraph from a Wikipedia page and extract the first sentence.
  assert fetch_first_sentence('https://en.wikipedia.org/wiki/Software_engineering') == 'Software engineering is the application of engineering to the design, development, implementation, testing, and maintenance of software in a systematic method'
  assert fetch_first_sentence('https://en.wikipedia.org/wiki/Python_(programming_language)') == 'Python is an interpreted high-level general-purpose programming language.'
  assert fetch_first_sentence('https://en.wikipedia.org/wiki/Artificial_intelligence') == 'Artificial intelligence is intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and animals.'
output: import requests
  from bs4 import BeautifulSoup
  
  def fetch_first_sentence(url):
      response = requests.get(url)
      soup = BeautifulSoup(response.content, 'html.parser')
      first_paragraph = soup.find('p').text
      first_sentence = first_paragraph.split('.')[0] + '.'
      return first_sentence