in maven-wrapper/src/main/java/org/apache/maven/wrapper/Installer.java [125:137]
private List<Path> listDirs(Path distDir) throws IOException {
List<Path> dirs = new ArrayList<>();
if (Files.exists(distDir)) {
try (DirectoryStream<Path> dirStream = Files.newDirectoryStream(distDir)) {
for (Path file : dirStream) {
if (Files.isDirectory(file)) {
dirs.add(file);
}
}
}
}
return dirs;
}