assertTrue(matcher.matchesAllOf(s));
    assertFalse(matcher.matchesNoneOf(s));
    assertEquals("", matcher.removeFrom(s));
    assertEquals(Strings.repeat("z", s.length()), matcher.replaceFrom(s, 'z'));
    assertEquals(Strings.repeat("ZZ", s.length()), matcher.replaceFrom(s, "ZZ"));
    assertEquals("", matcher.trimFrom(s));
    assertEquals(s.length(), matcher.countIn(s));
  }

    assertTrue(matcher.matchesAllOf(s));
    assertFalse(matcher.matchesNoneOf(s));
    assertEquals("", matcher.removeFrom(s));
    assertEquals(Strings.repeat("z", s.length()), matcher.replaceFrom(s, 'z'));
    assertEquals(Strings.repeat("ZZ", s.length()), matcher.replaceFrom(s, "ZZ"));
    assertEquals("", matcher.trimFrom(s));
    assertEquals(s.length(), matcher.countIn(s));
  }

   *
   * <p><b>Warning:</b> If {@code to} represents an existing file, that file will be overwritten
   * with the contents of {@code from}. If {@code to} and {@code from} refer to the <i>same</i>
   * file, the contents of that file will be deleted.
   *
   * <p><b>{@link java.nio.file.Path} equivalent:</b> {@link

    if (isAndroid()) {
      /*
       * NPT fails under the old versions of Android we test under because it performs reflection on
       * ImmutableTable, which declares static methods that refer to Collector, which is unavailable
       * under such versions.
       *
       * We use a runtime check here instead of @AndroidIncompatible: @AndroidIncompatible operates

    /*
     * TODO(lowasser): consider checking for ImmutableAsList here
     * TODO(lowasser): consider checking for Multiset here
     */
    // Don't refer to ImmutableSortedSet by name so it won't pull in all that code
    if (elements instanceof ImmutableSet && !(elements instanceof SortedSet)) {
      @SuppressWarnings("unchecked") // all supported methods are covariant

 *
 * <p>This class is not intended as a direct analogue of any existing "option" or "maybe" construct
 * from other programming environments, though it may bear some similarities.
 *
 * <p>An instance of this class is serializable if its reference is absent or is a serializable
 * object.
 *

 *       as {@code findFirst()} or {@code iterator()} is invoked. (Even though {@code Stream}
 *       contains all the right method <i>signatures</i> to implement {@link Iterable}, it does not
 *       actually do so, to avoid implying repeat-iterability.) {@code FluentIterable}, on the other
 *       hand, is multiple-use, and does implement {@link Iterable}.
 *   <li>Streams offer many features not found here, including {@code min/max}, {@code distinct},

 * cancellation of the operation so far. The only way to extract the value or exception from a step
 * is by declaring that step to be the last step of the pipeline. Nevertheless, we refer to the
 * "value" of a successful step or the "result" (value or exception) of any step.
 *
 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable

     * concurrent read operation to see inconsistent data. This is made easier by the nature of the
     * read operations in Map. For example, no operation can reveal that the table has grown but the
     * threshold has not yet been updated, so there are no atomicity requirements for this with
     * respect to reads.
     *

    String input = "20";
    assertEquals("", Strings.repeat(input, 0));
    assertEquals("20", Strings.repeat(input, 1));
    assertEquals("2020", Strings.repeat(input, 2));
    assertEquals("202020", Strings.repeat(input, 3));

    assertEquals("", Strings.repeat("", 4));

    for (int i = 0; i < 100; ++i) {
      assertEquals(2 * i, Strings.repeat(input, i).length());
    }

    try {