docs: public float[] getQuantiles(final double[] fractions) {
      if (isEmpty()) { return null; }
      KllFloatsQuantileCalculator quant = null;
      final float[] quantiles = new float[fractions.length];
      for (int i = 0; i < fractions.length; i++) {
        final double fraction = fractions[i];
        if (fraction < 0.0 || fraction > 1.0) {
          throw new SketchesArgumentException("Fraction cannot be less than zero or greater than 1.0");
        }
        if      (fraction == 0.0) { quantiles[i] = minValue_; }
        else if (fraction == 1.0) { quantiles[i] = maxValue_; }
        else {
          if (quant == null) {
            quant = getQuantileCalculator();
          }
          quantiles[i] = quant.getQuantile(fraction);
        }
      }
      return quantiles;
    }