private final Collection<ToolingModelBuilder> builders = new AbstractCollection<ToolingModelBuilder>() {
        @Override
        public Iterator<ToolingModelBuilder> iterator() {
            return Iterators.transform(registrations.iterator(), RegistrationImpl::getBuilder);
        }

        @Override
        public int size() {
            return registrations.size();
        }
    };

          @Override
          public Iterator<Entry<Range<K>, V>> iterator() {
            return entryIterator();
          }

          @Override
          public boolean retainAll(Collection<?> c) {
            return removeEntryIf(not(in(c)));
          }

          @Override
          public int size() {
            return Iterators.size(iterator());
          }

          @Override

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);
    assertTrue(multiset.isEmpty());
  }

  public void testCopyOf_iterator_oneElement() {
    Iterator<String> iterator = Iterators.singletonIterator("a");
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);

        return set1.isEmpty() && set2.isEmpty();
      }

      @Override
      public UnmodifiableIterator<E> iterator() {
        return new AbstractIterator<E>() {
          final Iterator<? extends E> itr1 = set1.iterator();
          final Iterator<? extends E> itr2 = set2.iterator();

          @Override
          @CheckForNull
          protected E computeNext() {
            if (itr1.hasNext()) {

        return set1.isEmpty() && set2.isEmpty();
      }

      @Override
      public UnmodifiableIterator<E> iterator() {
        return new AbstractIterator<E>() {
          final Iterator<? extends E> itr1 = set1.iterator();
          final Iterator<? extends E> itr2 = set2.iterator();

          @Override
          @CheckForNull
          protected E computeNext() {
            if (itr1.hasNext()) {

          return AsMap.this;
        }

        @Override
        public Iterator<Entry<K, Collection<V>>> iterator() {
          return new AbstractIterator<Entry<K, Collection<V>>>() {
            final Iterator<Entry<K, Collection<V>>> backingIterator =
                unfiltered.asMap().entrySet().iterator();

            @Override
            @CheckForNull

      }
    }
  }

  /**
   * Returns an iterator over the elements contained in this collection, <i>in no particular
   * order</i>.
   *
   * <p>The iterator is <i>fail-fast</i>: If the MinMaxPriorityQueue is modified at any time after
   * the iterator is created, in any way except through the iterator's own remove method, the
   * iterator will generally throw a {@link ConcurrentModificationException}. Thus, in the face of

      }

      int oldCount = values.size();
      if (occurrences >= oldCount) {
        values.clear();
      } else {
        Iterator<V> iterator = values.iterator();
        for (int i = 0; i < occurrences; i++) {
          iterator.next();
          iterator.remove();
        }
      }
      return oldCount;
    }

    @Override
    public void clear() {
      multimap.clear();

      }

      int oldCount = values.size();
      if (occurrences >= oldCount) {
        values.clear();
      } else {
        Iterator<V> iterator = values.iterator();
        for (int i = 0; i < occurrences; i++) {
          iterator.next();
          iterator.remove();
        }
      }
      return oldCount;
    }

    @Override
    public void clear() {
      multimap.clear();

  SingletonImmutableSet(E element) {
    this.element = checkNotNull(element);
  }

  @Override
  public int size() {
    return 1;
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.singletonIterator(element);
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return element.equals(object);
  }