BasePath crawlDBPath = platform.makePath(workingPath, URL_DB_NAME);
if (!crawlDBPath.exists()) {
Pipe importPipe = new Pipe("import URLs");
importPipe = new Each(importPipe, new LoadUrlsFunction());
BasePath inputPath = platform.makePath(input);
Tap sourceTap = platform.makeTap(platform.makeTextScheme(), inputPath);
Tap sinkTap = platform.makeTap(platform.makeBinaryScheme(UrlDatum.FIELDS), crawlDBPath, SinkMode.REPLACE);
FlowConnector flowConnector = platform.makeFlowConnector();
Flow flow = flowConnector.connect(sourceTap, sinkTap, importPipe);