code: def save_sources(self, ex_info):
      base_dir = ex_info["base_dir"]
      source_info = []
      for s, m in ex_info["sources"]:
          abspath = os.path.join(base_dir, s)
          store_path, md5sum = self.find_or_save(
              abspath, self.source_dir
          )
          source_info.append(
              [s, os.path.relpath(store_path, self.basedir)]
          )
      return source_info
  
imports: import json
  import os
  import os.path
  import re
  from typing import Optional
  from sacred.commandline_options import cli_option
  from sacred.dependencies import get_digest
  from sacred.observers.base import RunObserver
  from sacred.serializer import flatten
  from sacred.utils import PathType
label_desc: Use image node_id 6 for calling the GoogleCloudStorageObserver obj's underlying member method code with example usage: obj.save_sources(ex_info) and returns: source_info