n = unique;
    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedSet}. If the {@code ImmutableSortedSet}
     * already contains {@code element}, then {@code add} has no effect. (only the previously added
     * element is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null

public final class Collections2 {
  private Collections2() {}

  /**
   * Returns the elements of {@code unfiltered} that satisfy a predicate. The returned collection is
   * a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting collection's iterator does not support {@code remove()}, but all other
   * collection methods are supported. When given an element that doesn't satisfy the predicate, the

          return oldValue;
        }
        // value changed
      }
    }
  }

  /**
   * Copies all of the mappings from the specified map to this map. The effect of this call is
   * equivalent to that of calling {@code put(k, v)} on this map once for each mapping from key
   * {@code k} to value {@code v} in the specified map. The behavior of this operation is undefined

        .addEqualityGroup(
            newDelegatingListWithEquals(LIST2),
            newProxyWithSubHandler1(LIST2), // Makes sure type of handler doesn't affect equality
            newProxyWithSubHandler2(LIST2))
        .addEqualityGroup(newDelegatingIterableWithEquals(LIST2)) // different interface
        .testEquals();
  }

import com.google.common.collect.testing.AbstractCollectionTester;
import org.junit.Ignore;

/**
 * Base class for multiset collection tests.
 *
 * @author Jared Levy
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class AbstractMultisetTester<E> extends AbstractCollectionTester<E> {
  protected final Multiset<E> getMultiset() {

 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class MapSizeTester<K, V> extends AbstractMapTester<K, V> {
  public void testSize() {

import com.google.common.testing.SerializableTester;
import java.util.Map;
import org.junit.Ignore;

/**
 * Basic serialization test for maps.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class MapSerializationTester<K, V> extends AbstractMapTester<K, V> {
  @CollectionFeature.Require(SERIALIZABLE)

      return;
    }
    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.close();
    assertThrows(IOException.class, () -> out.write(42));

    // Verify that write had no effect
    assertTrue(Arrays.equals(data, source.read()));
    out.reset();
  }

  public void testReset() throws Exception {
    byte[] data = newPreFilledByteArray(100);

 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class CollectionIsEmptyTester<E> extends AbstractCollectionTester<E> {
  @CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {

import java.util.Arrays;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for {@link SetMultimap#replaceValues}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class SetMultimapReplaceValuesTester<K, V>
    extends AbstractMultimapTester<K, V, SetMultimap<K, V>> {