History of supersede 2 changes

In crates/hub/src/flow.rs, lines 516–523 on 8597fb5ca16c06c328fcb45858cd4e579f621fc29f1abf2e338edc4a28ab75e2. 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 516,523:crates/hub/src/flow.rs.