input: Write a python function to create an API wrapper that fetches JSON data from a given URL and returns None if the response status code is not 200.
  assert api_wrapper('https://jsonplaceholder.typicode.com/posts/1') is not None
  assert api_wrapper('https://jsonplaceholder.typicode.com/invalid-url') is None
  assert type(api_wrapper('https://jsonplaceholder.typicode.com/posts/1')) == dict
output: import requests
  
  def api_wrapper(url):
      response = requests.get(url)
      if response.status_code == 200:
          return response.json()
      return None