@Override
        public FileVisitResult visitFile(Path path, BasicFileAttributes attrs) throws IOException {
          String filePathString = path.toString();
          if (filePathString.endsWith(".class")) {
            Long calculatedHash = myCalculatedHashes.get(filePathString);
            if (calculatedHash != null) {
              targetRootHashes.add(calculatedHash);
            }
            else {
              File file = path.toFile();
              long hash = getOutputFileHash(file, rootFile);
              targetRootHashes.add(hash);
              myCalculatedHashes.put(filePathString, hash);
            }
          }
          return FileVisitResult.CONTINUE;
        }
@Override
        public FileVisitResult visitFile(Path path, BasicFileAttributes attrs)