code: def _highlightBracket(self, bracket, qpart, block, columnIndex):
          
          try:
              matchedBlock, matchedColumnIndex = self._findMatchingBracket(bracket, qpart, block, columnIndex)
          except _TimeoutException:  # not found, time is over
              return[] # highlight nothing
  
          if matchedBlock is not None:
              self.currentMatchedBrackets = ((block, columnIndex), (matchedBlock, matchedColumnIndex))
              return [self._makeMatchSelection(block, columnIndex, True),
                      self._makeMatchSelection(matchedBlock, matchedColumnIndex, True)]
          else:
              self.currentMatchedBrackets = None
              return [self._makeMatchSelection(block, columnIndex, False)]
docs: Highlight bracket and matching bracket
          Return tuple of QTextEdit.ExtraSelection's