public int compare(@Nullable String first, @Nullable String second) {
      if (first == second) {
        return 0;
      } else if (first == null) {
        return -1;
      } else if (second == null) {
        return 1;
      } else if (first.length() != second.length()) {
        return first.length() - second.length();
      } else {
        return first.compareTo(second);
      }
    }
  }

   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] concat(
      T[] first, T[] second, Class<@NonNull T> type) {
    T[] result = newArray(type, first.length + second.length);
    arraycopy(first, 0, result, 0, first.length);

   * as a false predicate is found.
   *
   * <p><b>Discouraged:</b> Prefer using {@code first.and(second)}.
   */
  public static <T extends @Nullable Object> Predicate<T> and(
      Predicate<? super T> first, Predicate<? super T> second) {
    return new AndPredicate<>(Predicates.<T>asList(checkNotNull(first), checkNotNull(second)));
  }

  /**

   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] concat(
      T[] first, T[] second, Class<@NonNull T> type) {
    T[] result = newArray(type, first.length + second.length);
    arraycopy(first, 0, result, 0, first.length);

        InvertibleCryptographer first = securityResourceProvider.providePrimaryInvertibleCryptographer();
        InvertibleCryptographer second = securityResourceProvider.providePrimaryInvertibleCryptographer();

        assertNotNull(first);
        assertNotNull(second);
        assertSame(first, second);
        assertSame(invertibleCryptographer, first);
    }

    public void test_providePrimaryInvertibleCryptographer_consistency() {

        TestScriptEngine engine1 = new TestScriptEngine("first");
        TestScriptEngine engine2 = new TestScriptEngine("second");

        scriptEngineFactory.add("test", engine1);
        scriptEngineFactory.add("test", engine2);

        // Should get the second engine
        ScriptEngine retrieved = scriptEngineFactory.getScriptEngine("test");
        assertEquals(engine2, retrieved);
    }

    TestCallable secondCallable = new TestCallable(SettableFuture.<Void>create());
    Future<?> second = serializer.submitAsync(secondCallable, directExecutor());
    assertThat(secondCallable.called).isFalse();
    assertThat(second.toString()).contains(secondCallable.toString());
    firstFuture.set(null);
    assertThat(second.toString()).contains(secondCallable.future.toString());
  }

        scriptExecutor.addShutdownListener(listener1);

        // Add second listener (should replace first)
        TestShutdownListener listener2 = new TestShutdownListener();
        scriptExecutor.addShutdownListener(listener2);

        // Call shutdown
        scriptExecutor.shutdown();

        // Verify only second listener was called
        assertFalse(listener1.wasShutdownCalled());

        assertEquals("Second group should be AnotherTestGroup", AnotherTestGroup.class, multiAnnotation.groups()[1]);

        assertEquals("Should have 2 payloads", 2, multiAnnotation.payload().length);
        assertEquals("First payload should be TestPayload", TestPayload.class, multiAnnotation.payload()[0]);

      long burst = measureTotalTimeMillis(limiter, oneSecWorthOfWork, new Random());
      // we allow one second worth of work to go in a burst (i.e. take less than a second)
      assertTrue(burst <= 1000);
      long afterBurst = measureTotalTimeMillis(limiter, oneSecWorthOfWork, new Random());
      // but work beyond that must take at least one second
      assertTrue(afterBurst >= 1000);
    }
  }

  /**