code: def get_epithet_index():
      """Return dict of epithets (key) to a set of all author ids of that
      epithet (value).
      """
      _dict = {}
      for k, v in AUTHOR_EPITHET.items():
          _dict[k] = set(v)
      return _dict
  
imports: import json
  import os
  import regex
  from cltk.corpora.grc.tlg.author_date import AUTHOR_DATE
  from cltk.corpora.grc.tlg.author_epithet import AUTHOR_EPITHET
  from cltk.corpora.grc.tlg.author_female import AUTHOR_FEMALE
  from cltk.corpora.grc.tlg.author_geo import AUTHOR_GEO
  from cltk.corpora.grc.tlg.id_author import ID_AUTHOR
  from cltk.corpora.grc.tlg.index_lists import INDEX_LIST
  from cltk.corpora.grc.tlg.work_numbers import WORK_NUMBERS
label_desc: Use image node_id 2 for calling a global function with example usage: get_epithet_index() and returns: _dict