void deleteEmptyParents(Path baseDir, Path targetParent) throws IOException {
if (!targetParent.startsWith(baseDir))
throw new IllegalArgumentException(targetParent + " does not start with " + baseDir);
void deleteEmptyParents(Path baseDir, Path targetParent) throws IOException {
if (!targetParent.startsWith(baseDir))
throw new IllegalArgumentException(targetParent + " does not start with " + baseDir);
if (!Files.isDirectory(targetParent))
throw new IllegalArgumentException(targetParent + " must be a directory");
boolean isA2target = Files.isSameFile(baseDir, targetParent);
if (!Files.isDirectory(targetParent))
throw new IllegalArgumentException(targetParent + " must be a directory");
boolean isA2target = Files.isSameFile(baseDir, targetParent);