Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. This method does not make sense for {@code BiMap}. This method exists only to

 * the License.
 */

package com.google.common.cache;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ExecutionException;

/**
 * A cache which forwards all its method calls to another cache. Subclasses should override one or

import static com.google.common.graph.GraphConstants.INNER_CAPACITY;
import static com.google.common.graph.GraphConstants.INNER_LOAD_FACTOR;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterators;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;

  }

  public void testMap() {
    MapJoiner j = Joiner.on(';').withKeyValueSeparator(':');
    assertEquals("", j.join(ImmutableMap.of()));
    assertEquals(":", j.join(ImmutableMap.of("", "")));

    Map<@Nullable String, @Nullable String> mapWithNulls = new LinkedHashMap<>();
    mapWithNulls.put("a", null);
    mapWithNulls.put(null, "b");

 *       of the type argument supplied by the user of the class: For example, {@code
 *       ImmutableMap.get} returns {@code @Nullable E} because the method can return {@code null}
 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>NullAway, which <a

 *       of the type argument supplied by the user of the class: For example, {@code
 *       ImmutableMap.get} returns {@code @Nullable E} because the method can return {@code null}
 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>NullAway, which <a

 *       of the type argument supplied by the user of the class: For example, {@code
 *       ImmutableMap.get} returns {@code @Nullable E} because the method can return {@code null}
 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>NullAway, which <a

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.util.concurrent.Futures.immediateFuture;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.Map;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;

 *       of the type argument supplied by the user of the class: For example, {@code
 *       ImmutableMap.get} returns {@code @Nullable E} because the method can return {@code null}
 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>NullAway, which <a

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.util.concurrent.Futures.immediateFuture;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.Map;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;