docs: def _readfile(cls, filename):
          """ Reads a file a utf-8 file,
              and retuns character tokens.
  
              :param filename: Name of file to be read.
          """
          f = codecs.open(filename, encoding='utf-8')
          filedata = f.read()
          f.close()
          tokenz = LM.tokenize(filedata, mode='c')
          #print tokenz
          return tokenz