code: public static BendableLongScore ofSoft(int hardLevelsSize, int softLevelsSize, int softLevel, long softScore) {
          long[] softScores = new long[softLevelsSize];
          softScores[softLevel] = softScore;
          return new BendableLongScore(0, new long[hardLevelsSize], softScores);
      }
docs: Creates a new {@link BendableLongScore}.
  @param hardLevelsSize at least 0
  @param softLevelsSize at least 0
  @param softLevel at least 0, less than softLevelsSize
  @param softScore any
  @return never null