code: def lib_directories(self):
          
          if self._lib_directories is None:
              self._lib_directories = []
              app_path = os.getcwd()
              contents = os.listdir(app_path)
              for c in contents:
                  # ensure content starts with lib, is directory, and is readable
                  if c.startswith('lib') and os.path.isdir(c) and (os.access(c, os.R_OK)):
                      self._lib_directories.append(c)
          return sorted(self._lib_directories, reverse=True)
docs: Get all "lib" directories.