*
 * <p>This uses the same efficient implementation as {@link Ordering#leastOf(Iterable, int)},
 * offering expected O(n + k log k) performance (worst case O(n log k)) for n calls to {@link
 * #offer} and a call to {@link #topK}, with O(k) memory. In comparison, quickselect has the same
 * asymptotics but requires O(n) memory, and a {@code PriorityQueue} implementation takes O(n log

      // requireNonNull is safe because the endpoint pair comes from the graph.
      copy.putEdgeValue(
          edge.nodeU(),
          edge.nodeV(),
          requireNonNull(graph.edgeValueOrDefault(edge.nodeU(), edge.nodeV(), null)));
    }
    return copy;
  }

  /** Creates a mutable copy of {@code network} with the same nodes and edges. */

      // requireNonNull is safe because the endpoint pair comes from the graph.
      copy.putEdgeValue(
          edge.nodeU(),
          edge.nodeV(),
          requireNonNull(graph.edgeValueOrDefault(edge.nodeU(), edge.nodeV(), null)));
    }
    return copy;
  }

  /** Creates a mutable copy of {@code network} with the same nodes and edges. */

   * This is an implementation of ImmutableMap optimized especially for Android, which does not like
   * objects per entry.  Instead we use an open-addressed hash table.  This design is basically
   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,

     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {
      if (nextElements.remove(e)) {
        nextElements.push(e);

   * multiset itself).
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * <p>This method is not type-safe, as it may be called on elements that are not mutually
   * comparable.
   *

        return next;
      }
    }
    return null;
  }

  /**
   * Determines whether two iterables contain equal elements in the same order. More specifically,
   * this method returns {@code true} if {@code iterable1} and {@code iterable2} contain the same
   * number of elements and every element of {@code iterable1} is equal to the corresponding element
   * of {@code iterable2}.
   */

   * that an abstract method is unimplemented. So instead we use a dynamic proxy to get an
   * implementation. If the method being called on the {@code TypeVariable} instance has the same
   * name as one of the public methods of {@link TypeVariableImpl}, the proxy calls the same method
   * on its instance of {@code TypeVariableImpl}. Otherwise it throws {@link
   * UnsupportedOperationException}; this should only apply to {@code getAnnotatedBounds()}. This

   * and returns that value on subsequent calls to {@code get()}. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at
   * most once unless the underlying {@code get()} throws an exception. The supplier's serialized

    }
  }

  /**
   * Returns a hash code, having the same bit length as each of the input hash codes, that combines
   * the information of these hash codes in an ordered fashion. That is, whenever two equal hash
   * codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
   * was computed from the <i>same</i> input hash codes in the <i>same</i> order.
   *