+ /// The txn_matched array should be set to references to transactions which matched the
+ /// relevant installed watch outpoints/txn, or the full set of transactions in the block.
+ ///
+ /// Note that if txn_matched includes only matched transactions, and a new
+ /// transaction/outpoint is watched during a block_connected call, the block *must* be
+ /// re-scanned with the new transaction/outpoints and block_connected should be called
+ /// again with the same header and (at least) the new transactions.
+ ///
+ /// Note that if non-new transaction/outpoints are be registered during a call, a second call