return suite;
  }

  Set<String> friends;
  Set<String> enemies;

  @Override
  public void setUp() {
    friends = Sets.newHashSet("Tom", "Joe", "Dave");
    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();

                }
            }
        }

        metadata = metadata.withVersioning(metadata.getVersioning().withSnapshotVersions(versions.values()));

        // just carry-on as-is
        if (recessive.getPlugins() != null && !recessive.getPlugins().isEmpty()) {
            metadata = metadata.withPlugins(new ArrayList<>(recessive.getPlugins()));
        }
    }

 * them as a {@link String}. Example:
 *
 * <pre>{@code
 * Joiner joiner = Joiner.on("; ").skipNulls();
 *  . . .
 * return joiner.join("Harry", null, "Ron", "Hermione");
 * }</pre>
 *
 * <p>This returns the string {@code "Harry; Ron; Hermione"}. Note that all input elements are
 * converted to strings using {@link Object#toString()} before being appended.
 *

 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface Supplier<T extends @Nullable Object>
{
  /**

                }
            }
        }

        metadata = metadata.withVersioning(metadata.getVersioning().withSnapshotVersions(versions.values()));

        // just carry-on as-is
        if (recessive.getPlugins() != null && !recessive.getPlugins().isEmpty()) {
            metadata = metadata.withPlugins(new ArrayList<>(recessive.getPlugins()));
        }

        artifacts.clear();

/**
 * Useful suppliers.
 *
 * <p>All methods return serializable suppliers as long as they're given serializable parameters.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Suppliers {
  private Suppliers() {}

  /**