History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on 8f0efa0729b02b703ca4caeb29ee53b6acd7c4e2e403f140617b26430d0e8570. 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.