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