CollectorTester<T, A, R> of(
          Collector<T, A, R> collector, BiPredicate<? super R, ? super R> equivalence) {
    return new CollectorTester<>(collector, equivalence);
  }

  private final Collector<T, A, R> collector;
  private final BiPredicate<? super R, ? super R> equivalence;

  private CollectorTester(

   * Collector} will be compared to the expected value using the specified {@code equivalence}.
   */
  public static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
      CollectorTester<T, A, R> of(
          Collector<T, A, R> collector, BiPredicate<? super R, ? super R> equivalence) {

        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);

    }

    SerializableTester.reserializeAndAssert(test.keySet());

    SerializableTester.reserializeAndAssert(nonEmptyRangeMap);
  }

  // TODO(b/172823566): Use mainline testToImmutableRangeMap once CollectorTester is usable to java7
  public void testToImmutableRangeMap() {
    Range<Integer> rangeOne = Range.closedOpen(1, 5);
    Range<Integer> rangeTwo = Range.openClosed(6, 7);

    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 static com.google.common.collect.Maps.immutableEntry;
import static org.junit.Assert.assertThrows;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.testing.CollectorTester;
import com.google.common.testing.SerializableTester;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**