code: public static List<Path> getSubDirectoryPathList(Path startDirectoryPath,
  			int maxDepth) {
  		return getSubPathList(startDirectoryPath, maxDepth,
  				DirectoryAndNotSymbolicLinkFilter);
  	}
docs: Gets sub directory path list.
  
  @param startDirectoryPath the start directory path
  @param maxDepth           the max depth
  @return the sub directory path list