private Booleans() {}

  /** Comparators for {@code Boolean} values. */
  private enum BooleanComparator implements Comparator<Boolean> {
    TRUE_FIRST(1, "Booleans.trueFirst()"),
    FALSE_FIRST(-1, "Booleans.falseFirst()");

    private final int trueValue;
    private final String toString;

    BooleanComparator(int trueValue, String toString) {
      this.trueValue = trueValue;
      this.toString = toString;
    }

  private Booleans() {}

  /** Comparators for {@code Boolean} values. */
  private enum BooleanComparator implements Comparator<Boolean> {
    TRUE_FIRST(1, "Booleans.trueFirst()"),
    FALSE_FIRST(-1, "Booleans.falseFirst()");

    private final int trueValue;
    private final String toString;

    BooleanComparator(int trueValue, String toString) {
      this.trueValue = trueValue;
      this.toString = toString;
    }