return new MutableClassToInstanceMap<>(new HashMap<Class<? extends @NonNull B>, B>());
  }

  /**
   * Returns a new {@code MutableClassToInstanceMap} instance backed by a given empty {@code
   * backingMap}. The caller surrenders control of the backing map, and thus should not allow any
   * direct references to it to remain accessible.
   */

                  @Override
                  @SuppressWarnings({"unchecked", "rawtypes"})
                  public Map<Class<?>, Impl> create(Object... elements) {
                    MutableClassToInstanceMap<Impl> map = MutableClassToInstanceMap.create();
                    for (Object object : elements) {
                      Entry<?, ?> entry = (Entry<?, ?>) object;

          return Integer.compare(left.getParameters().size(), right.getParameters().size());
        }
      };

  private final MutableClassToInstanceMap<Object> defaultValues =
      MutableClassToInstanceMap.create();
  private final ListMultimap<Class<?>, Object> distinctValues = ArrayListMultimap.create();
  private final NullPointerTester nullPointerTester = new NullPointerTester();