new DiscreteDomain<Integer>() {
        @Override
        public Integer next(Integer value) {
          return integers().next(value);
        }

        @Override
        public Integer previous(Integer value) {
          return integers().previous(value);
        }

        @Override
        public long distance(Integer start, Integer end) {

        assertFalse(mockService.unregisterWitness("non-existent"));
        assertFalse(mockService.processHeartbeat("non-existent", 1));

        // Test registration with null/empty values
        String regId1 = mockService.registerWitness(null, "192.168.1.100", 1);
        assertNotNull(regId1);

        String regId2 = mockService.registerWitness("", "192.168.1.100", 1);
        assertNotNull(regId2);

<div class="wrapper">
    <jsp:include page="/WEB-INF/view/common/admin/header.jsp"></jsp:include>
    <jsp:include page="/WEB-INF/view/common/admin/sidebar.jsp">
        <jsp:param name="menuCategoryType" value="system"/>
        <jsp:param name="menuType" value="dict"/>
    </jsp:include>
    <main class="content-wrapper">
        <div class="content-header">
            <div class="container-fluid">
                <div class="row mb-2">

    expectAdded(containsNullValue.get(0));
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutAll_nullValueUnsupported() {
    assertThrows(NullPointerException.class, () -> putAll(containsNullValue));
    expectUnchanged();
    expectNullValueMissingWhenNullValuesUnsupported(
        "Should not contain null value after unsupported putAll(containsNullValue)");
  }

    Optional<Integer> optionalInt = getSomeOptionalInt();
    // Number value = optionalInt.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError2() {
    FluentIterable<? extends Number> numbers = getSomeNumbers();
    Optional<? extends Number> first = numbers.first();
    // Number value = first.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test

    return File.createTempFile("test", null, getTempDir());
  }

  /** Returns a byte array of length size that has values 0 .. size - 1. */
  static byte[] newPreFilledByteArray(int size) {
    return newPreFilledByteArray(0, size);
  }

  /** Returns a byte array of length size that has values offset .. offset + size - 1. */
  static byte[] newPreFilledByteArray(int offset, int size) {
    byte[] array = new byte[size];

        multimap.putAll("bar", asList(4, 5));
        multimap.putAll("foo", asList(6));
        return multimap.values().iterator();
      }

      @Override
      protected void verify(List<Integer> elements) {
        assertEquals(elements, new ArrayList<>(multimap.values()));
      }
    }.test();
  }

  @GwtIncompatible // unreasonably slow
  public void testKeySetIteration() {

    @Override
    public String toString() {
        return "CrawlingInfoParam [crawlingInfo=" + crawlingInfo + ", crawlingInfoId=" + crawlingInfoId + ", createdTime=" + createdTime
                + ", key=" + key + ", value=" + value + ", docMeta=" + docMeta + "]";
    }

   */
  public static <T> java.util.Optional<T> findLast(Stream<T> stream) {
    final class OptionalState {
      boolean set = false;
      @Nullable T value = null;

      void set(T value) {
        this.set = true;
        this.value = value;
      }

      T get() {
        /*
         * requireNonNull is safe because we call get() only if we've previously called set().
         *

    }
  }

  private final class MockCallback implements FutureCallback<String> {
    @Nullable private String value = null;
    @Nullable private Throwable failure = null;
    private boolean wasCalled = false;
    private final Object monitor = new Object();

    MockCallback(String expectedValue) {
      this.value = expectedValue;
    }

    MockCallback(Throwable expectedFailure) {
      this.failure = expectedFailure;