docs: def rehighlight(self):
          """
          Rehighlight the entire document, may be slow.
          """
          start = time.time()
          QtWidgets.QApplication.setOverrideCursor(
              QtGui.QCursor(QtCore.Qt.WaitCursor))
          try:
              super(SyntaxHighlighter, self).rehighlight()
          except RuntimeError:
              # cloned widget, no need to rehighlight the same document twice ;)
              pass
          QtWidgets.QApplication.restoreOverrideCursor()
          end = time.time()
          _logger().debug('rehighlight duration: %fs' % (end - start))