def addReader(self, reader):
        """
        Implement L{IReactorFDSet.addReader}.
        """
        fd = reader.fileno()
        if fd not in self._reads:
            try:
                self._updateRegistration(fd, KQ_FILTER_READ, KQ_EV_ADD)
            except __HOLE__:
                pass
            finally:
                self._selectables[fd] = reader
                self._reads.add(fd)
dataset/ETHPy150Open twisted/twisted/twisted/internet/kqreactor.py/KQueueReactor.addReader