import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

// Confirmed by registry <******@****.***> (with technical
// reservations) 2008-07-01
de

// dj : https://en.wikipedia.org/wiki/.dj
dj

// dk : https://en.wikipedia.org/wiki/.dk
// Confirmed by registry <robert@dk-hostmaster.dk> 2008-06-17
dk

// dm : https://en.wikipedia.org/wiki/.dm
dm
com.dm
net.dm
org.dm
edu.dm
gov.dm

// do : https://en.wikipedia.org/wiki/.do
do
art.do
com.do

 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#multimaps">{@code
 * Multimaps}</a>.
 *
 * @author Jared Levy
 * @author Robert Konigsberg
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Multimaps {
  private Multimaps() {}