When adding links which point to resources within git repositories, like
  KEPs or supporting documentation, please reference a specific commit and avoid
  linking directly to the master branch. This ensures that links reference a
  specific point in time, rather than a document that may change over time.
  

## Changelog since v1.5.5

### Other notable changes

* kube-up (with gce/gci and gce/coreos providers) now ensures the authentication token file contains correct tokens for the control plane components, even if the file already exists (ensures upgrades and downgrades work successfully) ([#43676](https://github.com/kubernetes/kubernetes/pull/43676), [@liggitt](https://github.com/liggitt))

      this.state = referent.state;
    }

    @Override
    public void finalizeReferent() {
      references.remove(this);
      state.closeIfLeaked();
    }
  }

  /** Ensures that {@code o} is not garbage collected until this point in the code. */
  @VisibleForTesting
  static void reachabilityFence(@Nullable Object o) {
    REACHABILITY_FENCE_CALLER.reachabilityFence(o);
  }

        if (this.transportContext.getConfig().isStrictResourceLifecycle()) {
            clearAttributeCache();
        }
    }

    /**
     * Ensures tree connection is established with optimized connection reuse.
     * @return active tree handle
     * @throws CIFSException if connection fails
     *
     */

    testClientPrematureDisconnect(TransferKind.END_OF_STREAM)
  }

  private fun testClientPrematureDisconnect(transferKind: TransferKind) {
    // Setting a low transfer speed ensures that stream discarding will time out.
    val builder =
      MockResponse
        .Builder()
        .throttleBody(6, 1, TimeUnit.SECONDS)
    transferKind.setBody(builder, "ABCDE\nFGHIJKLMNOPQRSTUVWXYZ", 1024)

- If upgrading Cluster Federation components from 1.3.x, please ensure your cluster name is a valid DNS label (#30956, @nikhiljindal)

     * Sum per-segment modCounts to avoid mis-reporting when elements are concurrently added and
     * removed in one segment while checking another, in which case the table was never actually
     * empty at any point. (The sum ensures accuracy up through at least 1<<31 per-segment
     * modifications before recheck.) Method containsValue() uses similar constructions for
     * stability checks.
     */
    long sum = 0L;

     * Sum per-segment modCounts to avoid mis-reporting when elements are concurrently added and
     * removed in one segment while checking another, in which case the table was never actually
     * empty at any point. (The sum ensures accuracy up through at least 1<<31 per-segment
     * modifications before recheck.) Method containsValue() uses similar constructions for
     * stability checks.
     */
    long sum = 0L;

    assertThat(expected).hasCauseThat().isInstanceOf(MyException.class);
    assertEquals(
        "Nothing should be logged", 0, aggregateFutureLogHandler.getStoredLogRecords().size());
  }

  /** Ensure that errors are always logged. */
  public void testAllAsList_logging_error() throws Exception {
    ExecutionException expected =
        assertThrows(
            ExecutionException.class,

    assertThat(expected).hasCauseThat().isInstanceOf(MyException.class);
    assertEquals(
        "Nothing should be logged", 0, aggregateFutureLogHandler.getStoredLogRecords().size());
  }

  /** Ensure that errors are always logged. */
  public void testAllAsList_logging_error() throws Exception {
    ExecutionException expected =
        assertThrows(
            ExecutionException.class,