History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on 6907a989e82a4f7554dff2b26b0cd053ff97958eb030b97b62542db1cb0d3bae. 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 59,61:crates/hub/src/protocol.rs.