fn transcript_row(value: &Value) -> Option<(SessionMessage, bool)>Expand description
One transcript row as the session’s message, or None for a row that is
not one. The flag says the row is a compaction boundary, which the read
counts.
The one row rule, shared by every read of a transcript. A resume walks the whole file and the paging span read walks a window of it, and a second copy of this is how the two would come to type the same row differently.