new_contents: """
  Get predictions by ids of user's news
  """
  
  
  def predict(first_id=None, second_id=None, third_id=None):
      """
      Get news predictions. If one of ids isn't specified,
      so replace it to most popular articles. If none of ids
      is specified, get most popular news.
      :param first_id: MongoDB id of first article
      :param second_id:
      :param third_id:
      :return: [{'id': '', 'url': '', 'title': ''}, ...]
      """
      pass
  
subject: Add basic predictions file