// validate all files and hold on to errors for a complete report if there are failures
        StreamSupport.stream(inputChanges.getFileChanges(getInputFiles()).spliterator(), false)
            .filter(f -> f.getChangeType() != ChangeType.REMOVED)
            .map(FileChange::getFile)
            .filter(file -> file.isDirectory() == false)
            .forEach(file -> {
                try {

        // incrementally evaluate input files
        StreamSupport.stream(inputChanges.getFileChanges(getInputFiles()).spliterator(), false)
            .filter(f -> f.getChangeType() != ChangeType.REMOVED)
            .forEach(fileChange -> {
                File file = fileChange.getFile();
                if (file.isDirectory()) {
                    return;
                }