Searches Google News.
        NOTE: Official Google News API is deprecated https://developers.google.com/news-search/?hl=en
        NOTE: Google limits the maximum number of documents per query to 100.
              Use multiple related queries to get a bigger corpus. 

        Args:
            query (str): The search term.
            category_label (str): The category to assign to the articles. These
                                  categories are the labels in the generated corpus

            num (Optional[int]): The numnber of results to return.

        Returns:
            articles: Array of tuples that contains article link & cateogory
                      ex. [('IPO','www.cs.columbia.edu')]

def google_news_search(self,query,category_label,num=50):
        '''
        Searches Google News.
        NOTE: Official Google News API is deprecated https://developers.google.com/news-search/?hl=en
        NOTE: Google limits the maximum number of documents per query to 100.
              Use multiple related queries to get a bigger corpus. 

        Args:
            query (str): The search term.
            category_label (str): The category to assign to the articles. These
                                  categories are the labels in the generated corpus

            num (Optional[int]): The numnber of results to return.

        Returns:
            articles: Array of tuples that contains article link & cateogory
                      ex. [('IPO','www.cs.columbia.edu')]
        '''

        url = 'https://news.google.com/news?hl=en&q='+self._encode_query(query) \
                +'&num='+str(num)+'&output=rss'

        rss = feedparser.parse(url)
        entries = rss['entries']
        articles = []

        for entry in entries:
            link = entry['link']
            articles.append((category_label,link))
        return articles