builder.setSafeRange(' ', '~');
    assertEquals("The_Quick_Brown_Fox_", builder.build().escape("The Quick Brown Fox!"));
  }

  public void testBuilderCreatesIndependentEscapers() {
    // Set up a simple builder and create the first escaper.
    Escapers.Builder builder = Escapers.builder();
    builder.setSafeRange('a', 'z');
    builder.setUnsafeReplacement("X");

    builder.setSafeRange(' ', '~');
    assertEquals("The_Quick_Brown_Fox_", builder.build().escape("The Quick Brown Fox!"));
  }

  public void testBuilderCreatesIndependentEscapers() {
    // Set up a simple builder and create the first escaper.
    Escapers.Builder builder = Escapers.builder();
    builder.setSafeRange('a', 'z');
    builder.setUnsafeReplacement("X");

    // (Unicode code points above \uFFFF are represented via surrogate pairs
    // which means they are treated as pairs of safe characters).
    builder.setSafeRange(Character.MIN_VALUE, '\uFFFD');
    // Unsafe characters are replaced with the Unicode replacement character.
    builder.setUnsafeReplacement("\uFFFD");

    /*

     *
     * @param safeMin the lowest 'safe' character
     * @param safeMax the highest 'safe' character
     * @return the builder instance
     */
    @CanIgnoreReturnValue
    public Builder setSafeRange(char safeMin, char safeMax) {
      this.safeMin = safeMin;
      this.safeMax = safeMax;
      return this;
    }

    /**