* any {@code Entry} instances already retrieved from the entry set (this is
   * implementation-dependent). Furthermore, implementations are not required to support
   * modifications to the entry set at all, and the {@code Entry} instances themselves don't even
   * have methods for modification. See the specific implementation class for more details on how
   * its entry set handles modifications.
   *

          .build();

  /**
   * type → implementation. Inherently mutable interfaces and abstract classes are mapped to their
   * default implementations and are "new"d upon get().
   */
  private static final ConcurrentMap<Class<?>, Class<?>> implementations = Maps.newConcurrentMap();

  private static <T> void setImplementation(Class<T> type, Class<? extends T> implementation) {

          .build();

  /**
   * type → implementation. Inherently mutable interfaces and abstract classes are mapped to their
   * default implementations and are "new"d upon get().
   */
  private static final ConcurrentMap<Class<?>, Class<?>> implementations = Maps.newConcurrentMap();

  private static <T> void setImplementation(Class<T> type, Class<? extends T> implementation) {

   * one of the predefined {@link Policies} or specify a custom implementation. Implementations must
   * be thread-safe.
   *
   * @since 13.0
   */
  public interface Policy {

    /**
     * Called when a potential deadlock is encountered. Implementations can throw the given {@code
     * exception} and/or execute other desired logic.
     *

 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingNavigableMap}.
 *

 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingMap}.
 *

 * override {@code putAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingMap}.
 *

                    }
                    return new StandardImplForwardingMap<>(map);
                  }
                })
            .named("ForwardingMap[LinkedHashMap] with standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.ALLOWS_NULL_VALUES,
                MapFeature.ALLOWS_NULL_KEYS,
                MapFeature.ALLOWS_ANY_NULL_QUERIES,

                    }
                    return new StandardImplForwardingMap<>(map);
                  }
                })
            .named("ForwardingMap[LinkedHashMap] with standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.ALLOWS_NULL_VALUES,
                MapFeature.ALLOWS_NULL_KEYS,
                MapFeature.ALLOWS_ANY_NULL_QUERIES,

   * graph implementations, this method should replace {@link #graph} with a new graph that includes
   * this node.
   */
  abstract void addNode(Integer n);

  /**
   * A proxy method that adds the edge {@code e} to the graph being tested. In case of Immutable
   * graph implementations, this method should replace {@link #graph} with a new graph that includes
   * this edge.