def file_set_ids
        @file_set_ids ||= begin
                            ActiveFedora::SolrService.query("{!field f=has_model_ssim}FileSet",
                                                            rows: 10_000,
                                                            fl: ActiveFedora.id_field,
                                                            fq: "{!join from=ordered_targets_ssim to=id}id:\"#{id}/list_source\"")
                                                     .flat_map { |x| x.fetch(ActiveFedora.id_field, []) }
                          end
      end
def file_set_ids
        @file_set_ids ||= begin
                            ActiveFedora::SolrService.query("{!field f=has_model_ssim}FileSet",
                                                            rows: 10_000,
                                                            fl: ActiveFedora.id_field,
                                                            fq: "{!join from=ordered_targets_ssim to=id}id:\"#{id}/list_source\"")
                                                     .flat_map { |x| x.fetch(ActiveFedora.id_field, []) }
                          end
      end
These are the file sets that belong to this work, but not necessarily
 in order.
 Arbitrarily maxed at 10 thousand; had to specify rows due to solr's default of 10