code: def from_url(cls, url, **kwargs):
      
      username = kwargs.get('username')
      password = kwargs.get('password')
      headers = kwargs.get('headers', {})
      auth = None
      path = kwargs.get('path', '/tmp/app.zip')
      dest = kwargs.get('dest', '/app')
      if username and password:
        auth = base64.b64encode(b'%s:%s' % (username, password))
      if auth:
        headers['Authorization'] = 'Basic %s' % auth.decode('utf8')
      r = request.get(url, headers=headers, stream=True)
      if r.status_code != 200:
        err_msg = 'Could not download resource from url (%s): %s'
        err_args = (r.status_code, url)
        raise errors.DownloadError(err_msg % err_args)
      with open('/tmp/app.zip', 'wb+') as f:
        chunks = r.iter_content(chunk_size=1024)
        [f.write(chunk) for chunk in chunks if chunk]
      return cls.from_zip(path, dest)
docs: Downloads a zipped app source code from an url.
  
      :param url: url to download the app source from
  
      Returns
        A project instance.