}
      ArrayList<Integer> nodeList = new ArrayList<>(network.nodes());
      for (int i = 0; i < NUM_EDGES; ++i) {
        // Parallel edges are allowed, so this should always succeed.
        assertThat(
                network.addEdge(
                    getRandomElement(nodeList, gen), getRandomElement(nodeList, gen), new Object()))
            .isTrue();
      }

      }
      ArrayList<Integer> nodeList = new ArrayList<>(network.nodes());
      for (int i = 0; i < NUM_EDGES; ++i) {
        // Parallel edges are allowed, so this should always succeed.
        assertThat(
                network.addEdge(
                    getRandomElement(nodeList, gen), getRandomElement(nodeList, gen), new Object()))
            .isTrue();
      }

  public static <V extends @Nullable Object> V getDone(Future<V> future) throws ExecutionException {
    /*
     * We throw IllegalStateException, since the call could succeed later. Perhaps we "should" throw
     * IllegalArgumentException, since the call could succeed with a different argument. Those
     * exceptions' docs suggest that either is acceptable. Google's Java Practices page recommends

    return whenAllComplete(asList(future1, moreFutures));
  }

  /**
   * Starts specifying how to combine {@link ClosingFuture}s into a single pipeline, assuming they
   * all succeed. If any fail, the resulting pipeline will fail.
   *
   * @throws IllegalStateException if a {@code ClosingFuture} has already been derived from any of

      long oldValue = atomic.get();
      if (oldValue == 0L || atomic.compareAndSet(oldValue, 0L)) {
        // only remove after setting to zero, to avoid concurrent updates
        map.remove(key, atomic);
        // succeed even if the remove fails, since the value was already adjusted
        return oldValue;
      }
    }
  }

  /**
   * If {@code (key, value)} is currently in the map, this method removes it and returns true;

          assertTrue(expectedSuccess);
        } catch (ArithmeticException e) {
          if (expectedSuccess) {
            failFormat(
                "expected divide(%s, %s, UNNECESSARY) to succeed; got ArithmeticException", p, q);
          }
        }
      }
    }
  }

  @GwtIncompatible // TODO
  public void testZeroDivIsAlwaysZero() {
    for (long q : NONZERO_LONG_CANDIDATES) {

    try {
      collection.add(sampleElement);
      fail("add succeeded on unmodifiable collection");
    } catch (UnsupportedOperationException expected) {
    }

    assertCollectionsAreEquivalent(copy, collection);

    try {
      collection.addAll(siblingCollection);
      fail("addAll succeeded on unmodifiable collection");
    } catch (UnsupportedOperationException expected) {
    }

      if (executed) {
        return;
      }
      executed = true;
      list = runnables;
      runnables = null; // allow GC to free listeners even if this stays around for a while.
    }
    // If we succeeded then list holds all the runnables we to execute. The pairs in the stack are
    // in the opposite order from how they were added so we need to reverse the list to fulfill our
    // contract.

  @Override
  public boolean isCancelled() {
    final Object localValue = value;
    return localValue instanceof Cancellation;
  }

  /**
   * {@inheritDoc}
   *
   * <p>If a cancellation attempt succeeds on a {@code Future} that had previously been {@linkplain
   * #setFuture set asynchronously}, then the cancellation will also be propagated to the delegate
   * {@code Future} that was supplied in the {@code setFuture} call.
   *

                  throw new IndexOutOfBoundsException();
                }
              })
          .toArray();
      fail();
    } catch (IndexOutOfBoundsException expected) {
      // success
    }
  }

  private static void assertTransformListIterator(List<String> list) {
    ListIterator<String> iterator = list.listIterator(1);
    assertEquals(1, iterator.nextIndex());