public ElasticStreamSlice loadOrCreateSlice(String streamName, SliceRange sliceRange) throws IOException {
        Arguments.check(sliceRange.start() >= Offsets.NOOP_OFFSET, "startOffset must be >= NOOP_OFFSET");
        Arguments.check(sliceRange.end() >= Offsets.NOOP_OFFSET, "endOffset must be >= NOOP_OFFSET");
        if (sliceRange.start() == Offsets.NOOP_OFFSET) {
            return newSlice(streamName);
        }
        return new DefaultElasticStreamSlice(streamManager.getStream(streamName), sliceRange);
    }
Load or create slice
- when startOffset is NOOP_OFFSET, then seal last active slice and create new slice.
- when startOffset != NOOP_OFFSET, then load slice.
core/src/main/scala/kafka/log/streamaspect/ElasticStreamSliceManager.java