public static <T extends @Nullable Object> UnmodifiableIterator<T> singletonIterator(
      @ParametricNullness T value) {
    return new SingletonIterator<>(value);
  }

  private static final class SingletonIterator<T extends @Nullable Object>
      extends UnmodifiableIterator<T> {
    private final T value;
    private boolean done;

    SingletonIterator(T value) {
      this.value = value;
    }

 */

package com.google.common.collect;

import static com.google.common.collect.Iterables.transform;
import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.Sets.newHashSet;
import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE;

import static com.google.common.collect.ImmutableMultiset.toImmutableMultiset;
import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static org.junit.Assert.assertThrows;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.misleadingSizeCollection;

    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);
  }

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ObjectArrays.newArray;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.testComparator;

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ObjectArrays.newArray;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.testComparator;

  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    E connectingEdge = getConnectingEdge();
    return (connectingEdge == null)
        ? ImmutableSet.<E>of().iterator()
        : Iterators.singletonIterator(connectingEdge);
  }

  @Override
  public int size() {
    return getConnectingEdge() == null ? 0 : 1;
  }

  @Override
  public boolean contains(@Nullable Object edge) {