protected final FlushAction<K, V, A> buildFlushAction(MapperPair<K, V, A> mapperPair) { final A actionKey = mapperPair.getActionKey(); final String prefix = getOutputFilePrefix(actionKey); final File flushDir = new File(outDir, prefix); return buildFlushAction( actionKey, flushDir, ResourceHelper.buildNameGenerator(prefix + "-", ".gz", numDigits, chainNum), maxPairs, buildFlushFileStrategy()); }