code: def each_object_id(collection):
      
      c_path = collection_path(collection)
      paths = glob('%s/*.%s' % (c_path, _ext))
      for path in paths:
          match = regex.match(r'.+/(.+)\.%s$' % _ext, path)
          yield match.groups()[0]
docs: Yields each object ID in the given ``collection``.
      The objects are not loaded.