code: def getallobjlists(idf, refname):
      
      dtls = idf.model.dtls
      objlists = []
      for i, fieldidds in enumerate(idf.idd_info):
          indexlist = []
          for j, fieldidd in enumerate(fieldidds):
              if 'object-list' in fieldidd:
                  if fieldidd['object-list'][0].upper() == refname.upper():
                      indexlist.append(j)
          if indexlist != []:
              objkey = dtls[i]
              objlists.append((objkey, refname, indexlist))
      return objlists
docs: get all object-list fields for refname
      return a list:
      [('OBJKEY', refname, fieldindexlist), ...] where
      fieldindexlist = index of the field where the object-list = refname