let to_json t: Yojson.Basic.json =
      let {name;
           filter_reads_with_n_cigar;
           filter_mismatching_base_and_quals;
           filter_bases_not_stored;
           parameters} = t in
      `Assoc [
        "name", `String name;
        "filter_reads_with_N_cigar", `Bool filter_reads_with_n_cigar;
        "filter_mismatching_base_and_quals", `Bool filter_mismatching_base_and_quals;
        "filter_bases_not_stored", `Bool filter_bases_not_stored;
        "parameters",
        `Assoc (List.map parameters ~f:(fun (a, b) -> a, `String b));
      ]