source_results = [
          result(id: 1, event_id: 1, race_id: 1, place: 1),
          result(id: 2, event_id: 1, race_id: 1, participant_id: 1, place: nil),
          result(id: 3, event_id: 1, race_id: 1, participant_id: 1, place: ""),
          result(id: 4, event_id: 1, race_id: 1, participant_id: 1, place: "DQ"),