assertThrows(IllegalArgumentException.class, () -> ImmutableBiMap.copyOf(map));
    assertThat(expected).hasMessageThat().containsMatch("1|2");
  }

  // TODO(b/172823566): Use mainline testToImmutableBiMap once CollectorTester is usable to java7.
  public void testToImmutableBiMap_java7_combine() {
    ImmutableBiMap.Builder<String, Integer> zis =
        ImmutableBiMap.<String, Integer>builder().put("one", 1);

    assertThat(set.comparator()).isEqualTo(STRING_LENGTH);
  }

  // TODO(b/172823566): Use mainline testToImmutableSortedSet once CollectorTester is usable.
  public void testToImmutableSortedSet_java7() {
    // Note that a Collector should generally enforce consistent comparator between builders
    ImmutableSortedSet.Builder<String> zis =

    ImmutableSet<String> copy = ImmutableSet.copyOf(sortedSet);
    assertThat(copy).isNotSameInstanceAs(sortedSet);
  }

  // TODO(b/172823566): Use mainline testToImmutableSet once CollectorTester is usable to java7.
  public void testToImmutableSet_java7() {
    ImmutableSet.Builder<String> zis = ImmutableSet.<String>builder().add("a", "b", "a");

        NullPointerException.class,
        () -> ImmutableListMultimap.copyOf((ArrayListMultimap<String, Integer>) input));
  }

  // TODO(b/172823566): Use mainline testToImmutableListMultimap once CollectorTester is usable.
  public void testToImmutableListMultimap_java7_combine() {
    ImmutableListMultimap.Builder<String, Integer> zis =
        ImmutableListMultimap.<String, Integer>builder().put("a", 1).put("b", 2);

        NullPointerException.class,
        () -> ImmutableList.sortedCopyOf(String.CASE_INSENSITIVE_ORDER, (Collection<String>) c));
  }

  // TODO(b/172823566): Use mainline testToImmutableList once CollectorTester is usable to java7.
  public void testToImmutableList_java7_combine() {
    ImmutableList.Builder<String> zis = ImmutableList.<String>builder().add("a", "b");

    TypeWithDuplicates c = new TypeWithDuplicates(3, 1);
    CollectorTester.of(collector, equivalence)
        .expectCollects(
            ImmutableMultiset.<TypeWithDuplicates>builder().add(a).addCopies(b1, 2).add(c).build(),
            a,
            b1,
            c,
            b2);
    collector = toImmutableMultiset(e -> e, e -> 1);
    CollectorTester.of(collector, equivalence)
        .expectCollects(

import com.google.common.collect.testing.MapTestSuiteBuilder;
import com.google.common.collect.testing.TestEnumMapGenerator;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.testing.CollectorTester;
import com.google.common.truth.Truth;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Spliterator;
import java.util.stream.Collector;
import java.util.stream.Stream;

import com.google.common.collect.testing.google.SetGenerators.ImmutableSetUnsizedBuilderGenerator;
import com.google.common.collect.testing.google.SetGenerators.ImmutableSetWithBadHashesGenerator;
import com.google.common.testing.CollectorTester;
import com.google.common.testing.EqualsTester;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import java.util.function.BiPredicate;

import com.google.common.collect.testing.google.SortedMapGenerators.ImmutableSortedMapValueListGenerator;
import com.google.common.testing.CollectorTester;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;

import com.google.common.collect.testing.google.TestStringMultisetGenerator;
import com.google.common.collect.testing.google.UnmodifiableCollectionTests;
import com.google.common.testing.CollectorTester;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;