return union(emptySet(), newHashSet(elements));
                  }
                })
            .named("empty U set")
            .withFeatures(
                CollectionSize.ONE, CollectionSize.SEVERAL, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.google.ReflectionFreeAssertThrows.assertThrows;
import static java.util.Arrays.asList;

      assertOneToOne();
    } catch (UnsupportedOperationException tolerated) {
    }
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_threeToThree_addSupported() {
    assertThreeToThree();
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testSetCount_threeToThree_removeSupported() {
    assertThreeToThree();

      assertOneToOne();
    } catch (UnsupportedOperationException tolerated) {
    }
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCount_threeToThree_addSupported() {
    assertThreeToThree();
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testSetCount_threeToThree_removeSupported() {
    assertThreeToThree();

  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAllIgnoresCount() {
    initThreeCopies();
    assertTrue(getMultiset().removeAll(singleton(e0())));
    assertEmpty(getMultiset());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRetainAllIgnoresCount() {

  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAllIgnoresCount() {
    initThreeCopies();
    assertTrue(getMultiset().removeAll(singleton(e0())));
    assertEmpty(getMultiset());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRetainAllIgnoresCount() {

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.testers.ReflectionFreeAssertThrows.assertThrows;

import com.google.common.annotations.GwtCompatible;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.testers.ReflectionFreeAssertThrows.assertThrows;

import com.google.common.annotations.GwtCompatible;

                  }
                })
            .named("ArrayTable.rowKeySet")
            .withFeatures(
                CollectionSize.ONE,
                CollectionSize.SEVERAL,
                CollectionFeature.KNOWN_ORDER,
                CollectionFeature.REJECTS_DUPLICATES_AT_CREATION,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

 *       example {@link #anyMatch})
 *   <li>conversion methods which copy the {@code FluentIterable}'s contents into a new collection
 *       or array (for example {@link #toList})
 * </ul>
 *
 * <p>Several lesser-used features are currently available only as static methods on the {@link
 * Iterables} class.
 *
 * <p><a id="streams"></a>
 *
 * <h3>Comparison to streams</h3>
 *