code: def update_dois(self):
          
          dois = record_get_field_instances(self.record, '024', ind1="7")
          all_dois = {}
          for field in dois:
              subs = field_get_subfield_instances(field)
              subs_dict = dict(subs)
              if subs_dict.get('a'):
                  if subs_dict['a'] in all_dois:
                      record_delete_field(self.record, tag='024', ind1='7', field_position_global=field[4])
                      continue
                  all_dois[subs_dict['a']] = field
docs: Remove duplicate BibMatch DOIs.