return getEntryNullReplaces().getValue();
  }

  protected K getKeyForNullValue() {
    return getEntryNullReplaces().getKey();
  }

  private Entry<K, V> getEntryNullReplaces() {
    Iterator<Entry<K, V>> entries = getSampleElements().iterator();
    for (int i = 0; i < getNullLocation(); i++) {
      entries.next();
    }
    return entries.next();
  }

  protected void initMultimapWithNullKey() {

    IncidentEdgeSet<N> incident =
        new IncidentEdgeSet<N>(this, node, IncidentEdgeSet.EdgeType.BOTH) {
          @Override
          public Iterator<EndpointPair<N>> iterator() {
            return connections.incidentEdgeIterator(node);
          }
        };
    return nodeInvalidatableSet(incident, node);
  }

  @Override

  private int position;

  /** Returns the element with the specified index. This method is called by {@link #next()}. */
  @ParametricNullness
  protected abstract E get(int index);

  /**
   * Constructs an iterator across a sequence of the given size whose initial position is 0. That
   * is, the first call to {@link #next()} will return the first element (or throw {@link
   * NoSuchElementException} if {@code size} is zero).
   *

   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return collection.iterator();
      }
    };
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableDoubleArray.of())

      Iterable<T> unmodifiable, Iterable<T> modifiable) {
    UnmodifiableCollectionTests.assertIteratorIsUnmodifiable(unmodifiable.iterator());
    UnmodifiableCollectionTests.assertIteratorsInOrder(
        unmodifiable.iterator(), modifiable.iterator());
  }

  public void testInvertFrom() {
    ImmutableMultimap<Integer, String> empty = ImmutableMultimap.of();

        } else if (targetLocations == null) {
            locations = sourceLocations;
        } else {
            locations = new java.util.LinkedHashMap<>();
            for (java.util.Iterator<Integer> it = indices.iterator(); it.hasNext(); ) {
                InputLocation location;
                Integer index = it.next();
                if (index.intValue() < 0) {

            java.util.List expressions = getExpressions();

            if ( expressions != null && !expressions.isEmpty() )
            {
                for ( java.util.Iterator it = expressions.iterator(); it.hasNext(); )
                {
                    Expression expr = (Expression) it.next();

                    expressionsBySyntax.put( expr.getSyntax(), expr );
                }
            }

    List<K> keys = copyToList(multimap().keySet());
    for (K key : keys) {
      resetContainer();

      int size = getNumElements();

      Iterator<Entry<K, Collection<V>>> asMapItr = multimap().asMap().entrySet().iterator();
      Collection<V> collection = null;
      while (asMapItr.hasNext()) {
        Entry<K, Collection<V>> asMapEntry = asMapItr.next();
        if (key.equals(asMapEntry.getKey())) {

    int copyIntoArray(@Nullable Object[] dst, int offset) {
      return entries.copyIntoArray(dst, offset);
    }

    @Override
    public UnmodifiableIterator<Entry<K, V>> iterator() {
      return entries.iterator();
    }

    @Override
    ImmutableList<Entry<K, V>> createAsList() {
      return entries;
    }

    // redeclare to help optimizers with b/310253115

  private int position;

  /** Returns the element with the specified index. This method is called by {@link #next()}. */
  @ParametricNullness
  protected abstract E get(int index);

  /**
   * Constructs an iterator across a sequence of the given size whose initial position is 0. That
   * is, the first call to {@link #next()} will return the first element (or throw {@link
   * NoSuchElementException} if {@code size} is zero).
   *