def _fill_to(self, index):
        if self._last >= index:
            return True

        while self._last < index:
            try:
                n = next(self._origin)
            except __HOLE__:
                return False

            self._last += 1
            self._collection.append(n)

        return True
dataset/ETHPy150Open kachayev/fn.py/fn/stream.py/Stream._fill_to