IllegalStateException ex = new IllegalStateException(re);

    assertThat(getCausalChain(ex)).containsExactly(ex, re, iae, sue).inOrder();
    assertSame(sue, Iterables.getOnlyElement(getCausalChain(sue)));

    List<Throwable> causes = getCausalChain(ex);
    assertThrows(UnsupportedOperationException.class, () -> causes.add(new RuntimeException()));
  }

      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!
      // asserts that all get calling threads received the same value
      Object result = Iterables.getOnlyElement(finalResults);
      if (result == CancellationException.class) {
        assertTrue(future.isCancelled());
        if (future.wasInterrupted()) {

    IllegalStateException ex = new IllegalStateException(re);

    assertThat(getCausalChain(ex)).containsExactly(ex, re, iae, sue).inOrder();
    assertSame(sue, Iterables.getOnlyElement(getCausalChain(sue)));

    List<Throwable> causes = getCausalChain(ex);
    assertThrows(UnsupportedOperationException.class, () -> causes.add(new RuntimeException()));
  }

import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.Iterables.getOnlyElement;
import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.NEXT_HIGHER;

      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!
      // asserts that all get calling threads received the same value
      Object result = Iterables.getOnlyElement(finalResults);
      if (result == CancellationException.class) {
        assertTrue(future.isCancelled());
        if (future.wasInterrupted()) {

    }
  }

  public void testWriteThroughEntry() {
    for (LoadingCache<Object, Object> cache : caches()) {
      cache.getUnchecked(1);
      Entry<Object, Object> entry = Iterables.getOnlyElement(cache.asMap().entrySet());

      cache.invalidate(1);
      assertEquals(0, cache.size());

      entry.setValue(3);
      assertEquals(1, cache.size());
      assertEquals(3, cache.getIfPresent(1));

   *     iterator is unspecified.
   */
  @ParametricNullness
  public static <T extends @Nullable Object> T getOnlyElement(
      Iterator<? extends T> iterator, @ParametricNullness T defaultValue) {
    return iterator.hasNext() ? getOnlyElement(iterator) : defaultValue;
  }

  /**
   * Copies an iterator's elements into an array. The iterator will be left exhausted: its {@code

    assertThat(suppressed[1]).hasCauseThat().isInstanceOf(IllegalStateException.class);
    assertThat(suppressed[1]).hasCauseThat().hasMessageThat().isEqualTo("start failure");
    LogRecord record = Iterables.getOnlyElement(logHandler.getStoredLogRecords());
    // We log failures that occur after startup
    assertThat(record.getMessage())
        .contains("Service FailRunService [FAILED] has failed in the RUNNING state");
  }