code: static final void validateValues(final float[] values) {
      for (int i = 0; i < values.length ; i++) {
        if (Float.isNaN(values[i])) {
          throw new SketchesArgumentException("Values must not be NaN");
        }
        if ((i < (values.length - 1)) && (values[i] >= values[i + 1])) {
          throw new SketchesArgumentException(
            "Values must be unique and monotonically increasing");
        }
      }
    }
docs: Checks the sequential validity of the given array of float values.
  They must be unique, monotonically increasing and not NaN.
  @param values the given array of values