code: def normalize(self, text):
          
          #print 'Normalize...\n'
          text = text.lower()
          text = unicodedata.normalize('NFC', text)
          text = self.strip_mentions_links(text)
          return text
docs: Normalizes text.
              Converts to lowercase,
              Unicode NFC normalization
              and removes mentions and links
  
              :param text: Text to be normalized.