code: def _get_document(self, source):
          
          scheme_url = source
          if not source.startswith("http"):
              scheme_url = "http://%s" % source
  
          text = source
  
          try:
              text = urllib.urlopen(scheme_url).read()
          except:
              pass
          else:
              return (text, scheme_url)
  
          try:
              text = open(source, "r").read()
          except:
              pass
          else:
              return (text, source)
  
          return (text, None)
docs: helper, open a file or url and return the content and identifier