History of HubBackend::caller 3 changes

In crates/hub/src/protocol.rs, lines 62–88 on eb0c44a9ad3782c027b106258eef6d5c1dafd074ce2bfad37f4af0e8f6ed8e2d. 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 62,88:crates/hub/src/protocol.rs.