return true;
    }
    return hasCycle(network.asGraph());
  }

  /**
   * Performs a traversal of the nodes reachable from {@code startNode}. If we ever reach a node
   * we've already visited (following only outgoing edges and without reusing edges), we know
   * there's a cycle in the graph.
   */
  private static <N> boolean subgraphHasCycle(

    // objects indefinitely.
    private void drainQueue() {
      Reference<? extends L> ref;
      while ((ref = queue.poll()) != null) {
        // We only ever register ArrayReferences with the queue so this is always safe.
        ArrayReference<? extends L> arrayRef = (ArrayReference<? extends L>) ref;

      return true;
    }
    return hasCycle(network.asGraph());
  }

  /**
   * Performs a traversal of the nodes reachable from {@code startNode}. If we ever reach a node
   * we've already visited (following only outgoing edges and without reusing edges), we know
   * there's a cycle in the graph.
   */
  private static <N> boolean subgraphHasCycle(

      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*

  }

  /**
   * Returns whether any threads are waiting to enter this monitor. Note that because cancellations
   * may occur at any time, a {@code true} return does not guarantee that any other thread will ever
   * enter this monitor. This method is designed primarily for use in monitoring of the system
   * state.
   */
  public boolean hasQueuedThreads() {
    return lock.hasQueuedThreads();
  }

  /**

    private final Joiner joiner;
    private final String keyValueSeparator;

    private MapJoiner(Joiner joiner, String keyValueSeparator) {
      this.joiner = joiner; // only "this" is ever passed, so don't checkNotNull
      this.keyValueSeparator = checkNotNull(keyValueSeparator);
    }

    /**
     * Appends the string representation of each entry of {@code map}, using the previously

              // positive).
              bloomFilter.put(key);
              // False negative should *never* happen.
              assertThat(bloomFilter.mightContain(key)).isTrue();

              // If this check ever fails, that means we need to either bump the
              // number of expected insertions or don't run the test for so long.
              // Don't forget, the bloom filter slowly saturates over time and the

      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*

    internal val lengths: LongArray = LongArray(valueCount)
    internal val cleanFiles = mutableListOf<Path>()
    internal val dirtyFiles = mutableListOf<Path>()

    /** True if this entry has ever been published. */
    internal var readable: Boolean = false

    /** True if this entry must be deleted when the current edit or read completes. */
    internal var zombie: Boolean = false

    /**

    assertMoreInvariants(map);
  }

  @SuppressWarnings("CollectionIncompatibleType")
  private void assertEntrySetNotContainsString(Set<Entry<K, V>> entrySet) {
    // Very unlikely that a buggy collection would ever return true. It might accidentally throw.
    assertFalse(entrySet.contains("foo"));
  }

  /**
   * Override this to check invariants which should hold true for a particular implementation, but