History of supersede 2 changes

In crates/hub/src/flow.rs, lines 554–561 on 456f4197ade3c7be8561d727ed3ce28b309815ebe4a94765062ee3a9fb7575b2. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 554,561:crates/hub/src/flow.rs.