public boolean remove(@CheckForNull Object o) { // for performance
        return !LinkedListMultimap.this.removeAll(o).isEmpty();
      }
    }
    return new KeySetImpl();
  }

  @Override
  Multiset<K> createKeys() {
    return new Multimaps.Keys<K, V>(this);
  }

  /**
   * {@inheritDoc}
   *
   * <p>The iterator generated by the returned collection traverses the values in the order they

    }
    return changed;
  }

  static boolean removeAllImpl(Set<?> set, Collection<?> collection) {
    checkNotNull(collection); // for GWT
    if (collection instanceof Multiset) {
      collection = ((Multiset<?>) collection).elementSet();
    }
    /*
     * AbstractSet.removeAll(List) has quadratic behavior if the list size
     * is just more than the set's size.  We augment the test by