@Override
          protected char[] escapeUnsafe(int c) {
            return NO_CHARS;
          }
        };
    EscaperAsserts.assertBasic(escaper);
    assertThat(escaper.escape("\tFish & Chips\n")).isEqualTo("<tab>Fish <and> Chips<newline>");

    // Verify that everything else is left unescaped.
    String safeChars = "\0\u0100\uD800\uDC00\uFFFF";

          @Override
          protected char[] escapeUnsafe(char c) {
            return ("{" + c + "}").toCharArray();
          }
        };
    EscaperAsserts.assertBasic(wrappingEscaper);
    // '[' and '@' lie either side of [A-Z].
    assertThat(wrappingEscaper.escape("[FOO@BAR]")).isEqualTo("{[}FOO{@}BAR{]}");
  }

  public void testSafeRange_maxLessThanMin() throws IOException {

 */
@GwtCompatible
@NullUnmarked
public class EscapersTest extends TestCase {
  public void testNullEscaper() throws IOException {
    Escaper escaper = Escapers.nullEscaper();
    EscaperAsserts.assertBasic(escaper);
    String s = "\0\n\t\\az09~\uD800\uDC00\uFFFF";
    assertWithMessage("null escaper should have no effect").that(escaper.escape(s)).isEqualTo(s);
  }

  public void testBuilderInitialStateNoReplacement() {

  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {

  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {