code: def has_key(self, tag):
      return tag in self.tables
  
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 SFNTReader obj's underlying member method code with example usage: obj.has_key(tag) and returns: unknown