db5b65ca0d
Two branches of WalletSynchronizer had no coverage: the early-return in AnchorToCheckpointAsync when a range is already memoized (a second sync with a tx below the previously-anchored height must not re-walk the header chain), and the void RetryOnBusyAsync overload used by the transaction-download tasks (only the generic <T> overload, exercised by get_history, had a test).