} finally {
      closer.close();
    }
  }

  /**
   * Concatenates multiple {@link CharSource} instances into a single source. Streams returned from
   * the source will contain the concatenated data from the streams of the underlying sources.
   *
   * <p>Only one underlying stream will be open at a time. Closing the concatenated stream will
   * close the open underlying stream.
   *

    } finally {
      closer.close();
    }
  }

  /**
   * Concatenates multiple {@link CharSource} instances into a single source. Streams returned from
   * the source will contain the concatenated data from the streams of the underlying sources.
   *
   * <p>Only one underlying stream will be open at a time. Closing the concatenated stream will
   * close the open underlying stream.
   *

   * this map with the more specific generic type {@code Map<K, Set<V>>}, call {@link
   * Multimaps#asMap(SetMultimap)} instead.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.

    } finally {
      pool.shutdownNow();
    }

    // Since we have access to the backing map, verify that there are no zeroes in the map
    for (AtomicInteger value : map.values()) {
      assertTrue("map should not contain a zero", value.get() != 0);
    }
  }

  private static class MutateTask implements Callable<int[]> {
    private final ConcurrentHashMultiset<String> multiset;
    private final ImmutableList<String> keys;

   * this map with the more specific generic type {@code Map<K, Set<V>>}, call {@link
   * Multimaps#asMap(SetMultimap)} instead.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.

  public void testAdd_nullUnsupported() {
    assertThrows(NullPointerException.class, () -> collection.add(null));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported("Should not contain null after unsupported add(null)");
  }

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(absent = ZERO)
  public void testAddConcurrentWithIteration() {

    List<E> containsNull = singletonList(null);
    assertThrows(NullPointerException.class, () -> getList().addAll(0, containsNull));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported(
        "Should not contain null after unsupported addAll(n, containsNull)");
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testAddAllAtIndex_middle() {
    assertTrue(

  public void testAdd_nullUnsupported() {
    assertThrows(NullPointerException.class, () -> collection.add(null));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported("Should not contain null after unsupported add(null)");
  }

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  @CollectionSize.Require(absent = ZERO)
  public void testAddConcurrentWithIteration() {

    E[] expectedSubArray = createSamplesArray();
    for (int i = 0; i < getNumElements(); i++) {
      assertTrue(
          "toArray(overSizedE[]) should contain element " + expectedSubArray[i],
          subArray.contains(expectedSubArray[i]));
    }
    assertNull(
        "The array element immediately following the end of the collection should be nulled",
        array[getNumElements()]);

    inflater.inflate(buffer)
    assertThat(buffer.readUtf8()).isEqualTo("Hello inflation!")
  }

  /**
   * It's possible a self-terminating deflated message will contain trailing data that won't be
   * processed during inflation. If this happens, we need to either reject the message or discard
   * the unreachable data. We choose to discard it!
   *