     }
 #endif
     
-    /// Transaction hook
+    /// See sqlite3_update_hook
     private func didChange(with event: DatabaseEvent) {
         if savepointStack.isEmpty {
-            // Don't notify all transactionObservers about the database event.
-            // Only notify those that are interested in the event, and have been
-            // isolated in updateStatementWillExecute().
+            // Notify all interested transactionObservers.
             for observer in activeTransactionObservers {
                 observer.databaseDidChange(with: event)
             }

        }
    }
    
    /// Transaction hook
    private func didCommit() {
        savepointStack.clear()
        

    }
    
    func updateStatementWillExecute(_ statement: UpdateStatement) {
        // Grab the transaction observers that are interested in the actions
        // performed by the statement.
        let databaseEventKinds = statement.databaseEventKinds
        activeTransactionObservers = transactionObservers.filter { observer in
            return databaseEventKinds.contains(where: observer.observes)
        }
    }
    
