}

  private static <E> ImmutableList<E> copyFromCollection(Collection<? extends E> collection) {
    Object[] elements = collection.toArray();
    switch (elements.length) {
      case 0:
        return of();
      case 1:
        @SuppressWarnings("unchecked") // safe because it came from `collection`
        E element = (E) elements[0];
        return of(element);
      default:

import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.testing.SerializableTester;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for the {@code inverse} view of a BiMap.
 *
 * <p>This assumes that {@code bimap.inverse().inverse() == bimap}, which is not technically

import com.google.common.collect.Multiset;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.lang.ref.Reference;
import java.lang.ref.SoftReference;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * An implementation of {@link NetworkConnections} for undirected networks with parallel edges.

import com.google.common.collect.testing.SortedSetTestSuiteBuilder;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.Feature;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import junit.framework.TestSuite;

/**

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.ListFeature;
import java.util.Collections;
import java.util.List;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link List#replaceAll}. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.ListTestSuiteBuilder}.

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Collections;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/** Implementation of an {@link Optional} containing a reference. */
@GwtCompatible
final class Present<T> extends Optional<T> {

   *
   * @return set of column keys
   */
  Set<C> columnKeySet();

  /**
   * Returns a collection of all values, which may contain duplicates. Changes to the returned
   * collection will update the underlying table, and vice versa.
   *
   * @return collection of values
   */
  Collection<V> values();

  /**
   * Returns a view that associates each row key with the corresponding map from column keys to

   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return collection.iterator();
      }
    };
  }

  public void testEquals() {
    new EqualsTester()

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.function.BiPredicate;
import java.util.stream.Collector;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tester for {@code Collector} implementations.
 *
 * <p>Example usage:
 *
 * <pre>
 * CollectorTester.of(Collectors.summingInt(Integer::parseInt))

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static java.util.Objects.requireNonNull;

import java.util.Collections;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A base implementation of {@link NetworkConnections} for undirected networks.
 *
 * @author James Sexton