return new Joiner(separator);
  }

  /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
  public static Joiner on(char separator) {
    return new Joiner(String.valueOf(separator));
  }

  private final String separator;

  private Joiner(String separator) {
    this.separator = checkNotNull(separator);
  }

  private Joiner(Joiner prototype) {

   * {@code joiner}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code joiner.join(stream.iterator())}, or, if you are not
   * using any optional {@code Joiner} features, {@code
   * stream.collect(Collectors.joining(delimiter)}.
   *
   * @since 18.0
   */
  public final String join(Joiner joiner) {
    return joiner.join(this);
  }

  /**

  }

  private static final Joiner joiner = Joiner.on(", ");

  @Override
  protected void assertMoreInvariants(Map<K, V> map) {
    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + joiner.join(map.entrySet()) + "}", map.toString());

   * @param queue a reference queue that the thread will poll.
   * @param frqReference a phantom reference to the FinalizableReferenceQueue, which will be queued
   *     either when the FinalizableReferenceQueue is no longer referenced anywhere, or when its
   *     close() method is called.
   */
  public static void startFinalizer(
      Class<?> finalizableReferenceClass,
      ReferenceQueue<Object> queue,

  static final int DEFAULT_EDGE_COUNT = DEFAULT_NODE_COUNT * EXPECTED_DEGREE;

  // Load factor and capacity for "inner" (i.e. per node/edge element) hash sets or maps
  static final float INNER_LOAD_FACTOR = 1.0f;
  static final int INNER_CAPACITY = 2; // ceiling(EXPECTED_DEGREE / INNER_LOAD_FACTOR)

  // Error messages
  static final String NODE_NOT_IN_GRAPH = "Node %s is not an element of this graph.";

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.io;

import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableList;
import com.google.common.io.SourceSinkFactory.CharSinkFactory;
import java.io.IOException;
import java.io.Writer;
import java.lang.reflect.Method;

import javax.annotation.CheckForNull;

/**
 * Wraps an exception that occurred during a computation.
 *
 * @author Bob Lee
 * @since 2.0
 * @deprecated This exception is no longer thrown by {@code com.google.common}. Previously, it was
 *     thrown by {@link MapMaker} computing maps. When support for computing maps was removed from
 *     {@code MapMaker}, it was added to {@code CacheBuilder}, which throws {@code

 * limitations under the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;

import com.google.common.base.Joiner;
import com.google.common.util.concurrent.CycleDetectingLockFactory.Policies;
import com.google.common.util.concurrent.CycleDetectingLockFactory.Policy;

@ElementTypesAreNonnullByDefault
public class FinalizableReferenceQueue implements Closeable {
  /*
   * The Finalizer thread keeps a phantom reference to this object. When the client (for example, a
   * map built by MapMaker) no longer has a strong reference to this object, the garbage collector
   * will reclaim it and enqueue the phantom reference. The enqueued reference will trigger the
   * Finalizer to stop.
   *

 */

package com.google.common.testing;

import com.google.common.base.CharMatcher;
import com.google.common.base.Equivalence;
import com.google.common.base.Function;
import com.google.common.base.Joiner;
import com.google.common.base.Predicate;
import com.google.common.base.Splitter;
import com.google.common.base.Ticker;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.BiMap;