docs: private RekordboxAnlz.BeatGridTag findTag(RekordboxAnlz anlzFile) {
          for (RekordboxAnlz.TaggedSection section : anlzFile.sections()) {
              if (section.body() instanceof RekordboxAnlz.BeatGridTag) {
                  return (RekordboxAnlz.BeatGridTag) section.body();
              }
          }
          throw new IllegalArgumentException("No beat grid found inside analysis file " + anlzFile);
      }