assertEquals("Xhe_Xuick_Xrown_Xox_", builder.build().escape("The Quick Brown Fox!"));
    // Explicit replacements take priority over safe characters.
    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.