code: def _strip(text):
          
          text = text.strip()
          text = text.replace('  ', ' ')  # remove duplicate spaces
          text = text.lower()
          for joiner in TextTitle.JOINERS:
              text = text.replace(joiner, 'and')
          for article in TextTitle.ARTICLES:
              if text.startswith(article + ' '):
                  text = text[len(article) + 1:]
                  break
          return text
docs: Strip articles/whitespace and remove case.