assertEquals(multimap, input);
    assertEquals(input, multimap);
  }

  public void testCopyOfWithDuplicates() {
    ArrayListMultimap<Object, Object> input = ArrayListMultimap.create();
    input.put("foo", 1);
    input.put("bar", 2);
    input.put("foo", 3);
    input.put("foo", 1);
    ImmutableSetMultimap<Object, Object> copy = ImmutableSetMultimap.copyOf(input);

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ListMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.MutableClassToInstanceMap;

   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *
   * <p>Call this method only when the simpler methods {@link ArrayListMultimap#create()}, {@link
   * HashMultimap#create()}, {@link LinkedHashMultimap#create()}, {@link
   * LinkedListMultimap#create()}, {@link TreeMultimap#create()}, and {@link