* provide a better implementation than the input Collection, at least without dramatic changes
     * like copying it to a new Set—which might then test for element equality differently.
     */
    @SuppressWarnings("UndefinedEquals")
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof InPredicate) {
        InPredicate<?> that = (InPredicate<?>) obj;
        return target.equals(that.target);
      }

     * implement equals(), such as most Queue implementations, will get the same behavior from our
     * value-collection wrappers (and from Multimap.equals) as from the underlying Collection.
     */
    @SuppressWarnings("UndefinedEquals")
    public boolean equals(@Nullable Object object) {
      if (object == this) {
        return true;
      }
      refreshIfEmpty();
      return delegate.equals(object);
    }

    @Override

        }
        return keys;
      }
    }

    @Override
    // A forwarding implementation can't do any better than the underlying object.
    @SuppressWarnings("UndefinedEquals")
    public boolean equals(@Nullable Object o) {
      if (o == this) {
        return true;
      }
      synchronized (mutex) {
        return delegate().equals(o);
      }
    }

        }
        return keys;
      }
    }

    @Override
    // A forwarding implementation can't do any better than the underlying object.
    @SuppressWarnings("UndefinedEquals")
    public boolean equals(@Nullable Object o) {
      if (o == this) {
        return true;
      }
      synchronized (mutex) {
        return delegate().equals(o);
      }
    }