docs: def _get_library_os_path_from_library_dict_tree(self, library_path, library_name):
          """Hand verified library os path from libraries dictionary tree."""
          if library_path is None or library_name is None:
              return None
          path_list = library_path.split(os.sep)
          target_lib_dict = self.libraries
          # go down the path to the correct library
          for path_element in path_list:
              if path_element not in target_lib_dict:  # Library cannot be found
                  target_lib_dict = None
                  break
              target_lib_dict = target_lib_dict[path_element]
          return None if target_lib_dict is None or library_name not in target_lib_dict else target_lib_dict[library_name]