guava/src/com/google/common/io/MoreFiles.java
private static @Nullable Collection<IOException> deleteDirectoryContentsInsecure(
      DirectoryStream<Path> dir) {
    Collection<IOException> exceptions = null;
    try {
      for (Path entry : dir) {
        exceptions = concat(exceptions, deleteRecursivelyInsecure(entry));
      }

      return exceptions;
    } catch (DirectoryIteratorException e) {
      return addException(exceptions, e.getCause());
    }
  }
private static @Nullable Collection<IOException> deleteDirectoryContentsInsecure(
      DirectoryStream<Path> dir) {
    Collection<IOException> exceptions = null;
    try {
      for (Path entry : dir) {
        exceptions = concat(exceptions, deleteRecursivelyInsecure(entry));
      }

      return exceptions;
    } catch (DirectoryIteratorException e) {
      return addException(exceptions, e.getCause());
    }
  }
Simple, insecure method for deleting the contents of a directory for file systems that don't
support {@code SecureDirectoryStream}. Returns a collection of exceptions that occurred or null
if no exceptions were thrown.