fn group_reports_by_sink(
reports: Vec<PbIcebergPkIndexSinkMetadata>,
) -> MetaResult<HashMap<SinkId, (u64, Vec<PbIcebergPkIndexSinkMetadata>)>>fn group_reports_by_sink(
reports: Vec<PbIcebergPkIndexSinkMetadata>,
) -> MetaResult<HashMap<SinkId, (u64, Vec<PbIcebergPkIndexSinkMetadata>)>>