code: public UnixPath resolveSibling(UnixPath other) {
      checkNotNull(other);
      UnixPath parent = getParent();
      return parent == null ? other : parent.resolve(other);
    }
docs: Returns {@code other} resolved against parent of {@code path}.
  
  @see java.nio.file.Path#resolveSibling(java.nio.file.Path)