// Force close the handle
                this.open = false;
                this.usageCount.set(0);

                // Clear mutable references to free memory
                // Note: Some fields may be final and cannot be nulled

                // Clear any other mutable state would go here
            }
        } catch (Exception e) {
            log.error("Failed to perform emergency file handle cleanup", e);

   * @return an immutable set containing those elements, minus duplicates
   */
  public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(
      E anElement, E... otherElements) {
    return ImmutableEnumSet.asImmutable(EnumSet.of(anElement, otherElements));
  }

  /**
   * Returns an immutable set instance containing the given enum elements. Internally, the returned

   *     those lists should appear in the resulting lists
   * @param <B> any common base class shared by all axes (often just {@link Object})
   * @return the Cartesian product, as an immutable list containing immutable lists
   * @throws IllegalArgumentException if the size of the cartesian product would be greater than
   *     {@link Integer#MAX_VALUE}

    @Test
    @DisplayName("ltime field is mutable")
    void testLtimeField() {
        TestLocking t = new TestLocking();

        // Initial value
        assertEquals(0L, t.ltime, "ltime should start at 0");

        // Set new value
        long currentTime = System.currentTimeMillis();
        t.ltime = currentTime;
        assertEquals(currentTime, t.ltime, "ltime should be mutable");
    }

    @Test

        if (subgraph.nodes().contains(successorNode)) {
          subgraph.addEdge(node, successorNode, edge);
        }
      }
    }
    return subgraph;
  }

  /** Creates a mutable copy of {@code graph} with the same nodes and edges. */
  public static <N> MutableGraph<N> copyOf(Graph<N> graph) {
    MutableGraph<N> copy = GraphBuilder.from(graph).expectedNodeCount(graph.nodes().size()).build();

        if (subgraph.nodes().contains(successorNode)) {
          subgraph.addEdge(node, successorNode, edge);
        }
      }
    }
    return subgraph;
  }

  /** Creates a mutable copy of {@code graph} with the same nodes and edges. */
  public static <N> MutableGraph<N> copyOf(Graph<N> graph) {
    MutableGraph<N> copy = GraphBuilder.from(graph).expectedNodeCount(graph.nodes().size()).build();

      AvlNode<E> newRoot = new AvlNode<>(element, occurrences);
      successor(header, newRoot, header);
      rootReference.checkAndSet(root, newRoot);
      return 0;
    }
    int[] result = new int[1]; // used as a mutable int reference to hold result
    AvlNode<E> newRoot = root.add(comparator(), element, occurrences, result);
    rootReference.checkAndSet(root, newRoot);
    return result[0];
  }

  @CanIgnoreReturnValue

 *       mutable objects as elements at all, as many users may expect your "immutable" object to be
 *       <i>deeply</i> immutable.
 * </ul>
 *
 * <h4>Performance notes</h4>
 *
 * <ul>
 *   <li>Implementations can be generally assumed to prioritize memory efficiency, then speed of
 *       access, and lastly speed of creation.
 *   <li>The {@code copyOf} methods will sometimes recognize that the actual copy operation is

  /**
   * Reduces the memory used by this {@code ArrayListMultimap}, if feasible.
   *
   * @deprecated For a {@link ListMultimap} that automatically trims to size, use {@link
   *     ImmutableListMultimap}. If you need a mutable collection, remove the {@code trimToSize}
   *     call, or switch to a {@code HashMap<K, ArrayList<V>>}.
   */
  @Deprecated
  public void trimToSize() {
    for (Collection<V> collection : backingMap().values()) {

 *       mutable objects as elements at all, as many users may expect your "immutable" object to be
 *       <i>deeply</i> immutable.
 * </ul>
 *
 * <h4>Performance notes</h4>
 *
 * <ul>
 *   <li>Implementations can be generally assumed to prioritize memory efficiency, then speed of
 *       access, and lastly speed of creation.
 *   <li>The {@code copyOf} methods will sometimes recognize that the actual copy operation is