Array of string representations of rows that have been visited.
Whether or not we're still processing rows.
Defaults to true (processing rows), but is set to false once
rounds has been visited.
Visits a row. If we're still visiting (i.e. rounds hasn't been reached) then we pass that row to derived classes for processing.
Optionalblock: AbstractBlockProtectedvisit
Simple visitor that accumulates rows into an array of strings
Converts each visited row to a string and stores it. The visitor accumulates rows from a touch in the order they're rung.