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

    // Verify that everything else is left unescaped.
    String safeChars = "\0\u0100\uD800\uDC00\uFFFF";
    assertEquals(safeChars, escaper.escape(safeChars));

            .add("in", "the", "quick", "jumped", "over", "a")
            .build();
    assertTrue(set.headSet("a") instanceof ImmutableSortedSet);
    assertTrue(set.headSet("fish") instanceof ImmutableSortedSet);
    assertThat(set.headSet("fish")).containsExactly("a", "in", "the").inOrder();
    assertThat(set.headSet("california"))
        .containsExactly("a", "in", "the", "over", "quick", "jumped")
        .inOrder();

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

    // Verify that everything else is left unescaped.
    String safeChars = "\0\u0100\uD800\uDC00\uFFFF";
    assertEquals(safeChars, escaper.escape(safeChars));

            .add("in", "the", "quick", "jumped", "over", "a")
            .build();
    assertTrue(set.headSet("a") instanceof ImmutableSortedSet);
    assertTrue(set.headSet("fish") instanceof ImmutableSortedSet);
    assertThat(set.headSet("fish")).containsExactly("a", "in", "the").inOrder();
    assertThat(set.headSet("california"))
        .containsExactly("a", "in", "the", "over", "quick", "jumped")
        .inOrder();

    // Replacements are applied first regardless of whether the character is in
    // the safe range or not ('&' is a safe char while '\t' and '\n' are not).
    assertEquals(
        "<tab>Fish <and>? Chips?<newline>", replacingEscaper.escape("\tFish &\0 Chips\r\n"));
  }

broken.  She hastily put down the bottle, saying to herself
`That's quite enough--I hope I shan't grow any more--As it is, I
can't get out at the door--I do wish I hadn't drunk quite so
much!'

  Alas! it was too late to wish that!  She went on growing, and
growing, and very soon had to kneel down on the floor:  in
another minute there was not even room for this, and she tried

    // Replacements are applied first regardless of whether the character is in
    // the safe range or not ('&' is a safe char while '\t' and '\n' are not).
    assertEquals(
        "<tab>Fish <and>? Chips?<newline>", replacingEscaper.escape("\tFish &\0 Chips\r\n"));
  }

broken.  She hastily put down the bottle, saying to herself
`That's quite enough--I hope I shan't grow any more--As it is, I
can't get out at the door--I do wish I hadn't drunk quite so
much!'

  Alas! it was too late to wish that!  She went on growing, and
growing, and very soon had to kneel down on the floor:  in
another minute there was not even room for this, and she tried

   * {@code NavigableMap}. In many cases, you may wish to override {@link
   * ForwardingNavigableMap#descendingMap} to forward to this implementation or a subclass thereof.
   *
   * <p>In particular, this map iterates over entries with repeated calls to {@link
   * NavigableMap#lowerEntry}. If a more efficient means of iteration is available, you may wish to
   * override the {@code entryIterator()} method of this class.
   *

   * #clear} to forward to this implementation.
   *
   * @since 7.0
   */
  protected void standardClear() {
    Iterators.clear(iterator());
  }

  /**
   * A sensible definition of {@link #isEmpty} as {@code !iterator().hasNext}. If you override
   * {@link #isEmpty}, you may wish to override {@link #isEmpty} to forward to this implementation.