private final char startInclusive;
    private final char endInclusive;

    InRange(char startInclusive, char endInclusive) {
      checkArgument(endInclusive >= startInclusive);
      this.startInclusive = startInclusive;
      this.endInclusive = endInclusive;
    }

    @Override
    public boolean matches(char c) {
      return startInclusive <= c && c <= endInclusive;
    }