code: def fromString(self, str):
      sstruct.unpack(self.format, str, self)
  
imports: from io import BytesIO
  from types import SimpleNamespace
  from fontTools.misc.textTools import Tag
  from fontTools.misc import sstruct
  from fontTools.ttLib import TTLibError, TTLibFileIsCollectionError
  import struct
  from collections import OrderedDict
  import logging
label_desc: Use image node_id 3 for calling the DirectoryEntry obj's underlying member method code with example usage: obj.fromString(str) without return types