'Remove a Selectable for notification of data available to read.'

def removeReader(self, reader):

    if (reader in self._readers):
        fd = self._readers.pop(reader)
        (_, writer) = self._fds[fd]
        if writer:
            self._fds[fd] = (None, writer)
            self._io_loop.update_handler(fd, IOLoop.WRITE)
        else:
            del self._fds[fd]
            self._io_loop.remove_handler(fd)
