CombineTimestamp is used primarily to create a sequence of Timestamped<T> values for downstream operators, when timestamps have been extracted from other sources.

Alternatively, CombineTimestamp can be used to preserve the value of a timestamp during post-processing operations. In this case, even though the timestamped value may be transformed multiple times, we can keep the original acquisition timestamp in a branch and use the Zip operator followed by CombineTimestamp to carry the timestamp value forward.