private static final ImmutableMap<Character, String> SIMPLE_REPLACEMENTS =
      ImmutableMap.of(
          '\n', "<newline>",
          '\t', "<tab>",
          '&', "<and>");

  public void testSafeRange() throws IOException {
    // Basic escaping of unsafe chars (wrap them in {,}'s)
    CharEscaper wrappingEscaper =
        new ArrayBasedCharEscaper(NO_REPLACEMENTS, 'A', 'Z') {
          @Override

    // Ensure that Unicode escapers behave correctly wrt badly formed input.
    String badUnicode = "\uDC00\uD800";
    assertThrows(IllegalArgumentException.class, () -> escaper.escape(badUnicode));
  }

  public void testSafeRange() throws IOException {
    // Basic escaping of unsafe chars (wrap them in {,}'s)
    UnicodeEscaper wrappingEscaper =
        new ArrayBasedUnicodeEscaper(NO_REPLACEMENTS, 'A', 'Z', null) {
          @Override