*  New: Support `Expect: 100-continue` as a request header. Callers can use this header to
    pessimistically hold off on transmitting a request body until a server gives the go-ahead.
 *  New: Permit network interceptors to rewrite the host header for HTTP/2. This makes it possible
    to do domain fronting.
 *  New: charset support for `Credentials.basic()`.

## Changelog since v1.18.15

## Changes by Kind

### Bug or Regression

- Avoid marking node as Ready until node has synced with API servers at least once ([#99034](https://github.com/kubernetes/kubernetes/pull/99034), [@ehashman](https://github.com/ehashman)) [SIG Node]

			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            27,
			want:         26,
			wantErr:      io.EOF,
			wantBuffered: 0,
		},
		// Any error from filling shouldn't show up until we
		// get past the valid bytes. Here we return 5 valid bytes at the same time
		// as an error, but test that we don't see the error from Discard.
		{
			name: "fill error, discard less",

        }
        checkState(whenClosed == null);
        return whenClosed = new CountDownLatch(1);
      }
    }
  }

  /**
   * Returns an object that can be used to wait until this objects' deferred closeables have all had
   * {@link Runnable}s that close them submitted to each one's closing {@link Executor}.
   */
  @VisibleForTesting
  CountDownLatch whenClosedCountDown() {

    assertThat(countLiveEntries(map, 0)).isEqualTo(liveCount);
    ImmutableMap<Object, Object> originalMap = ImmutableMap.copyOf(map);
    assertThat(originalMap).hasSize(liveCount);
    // can't compare map contents until cleanup occurs

    for (int i = 1; i <= originalCount * 2; i *= 2) {
      if (i > 1) {
        segment.expand();
      }
      assertThat(segment.table.length()).isEqualTo(i);

    assertThat(countLiveEntries(map, 0)).isEqualTo(liveCount);
    ImmutableMap<Object, Object> originalMap = ImmutableMap.copyOf(map);
    assertThat(originalMap).hasSize(liveCount);
    // can't compare map contents until cleanup occurs

    for (int i = 1; i <= originalCount * 2; i *= 2) {
      if (i > 1) {
        segment.expand();
      }
      assertThat(segment.table.length()).isEqualTo(i);

    peer.sendFrame().settings(Settings())
    peer.acceptFrame() // SETTINGS ACK
    peer.acceptFrame() // SYN_STREAM on stream 1
    for (i in 0 until framesThatFillWindow) {
      peer.acceptFrame() // DATA on stream 1
    }
    peer.acceptFrame() // SYN_STREAM on stream 2
    peer.acceptFrame() // DATA on stream 2
    peer.play()

    // Play it back.

### Bug or Regression

- Aggregate errors when putting vmss ([#98350](https://github.com/kubernetes/kubernetes/pull/98350), [@nilo19](https://github.com/nilo19)) [SIG Cloud Provider]
- Avoid marking node as Ready until node has synced with API servers at least once ([#97996](https://github.com/kubernetes/kubernetes/pull/97996), [@ehashman](https://github.com/ehashman)) [SIG Node]

                    result.set(index, t);
                  }
                  gettersComplete.countDown();
                }
              });
      thread.start();
      // we want to wait until each thread is WAITING - one thread waiting inside CacheLoader.load
      // (in startSignal.await()), and the others waiting for that thread's result.
      while (thread.isAlive() && thread.getState() != Thread.State.WAITING) {

                    result.set(index, t);
                  }
                  gettersComplete.countDown();
                }
              });
      thread.start();
      // we want to wait until each thread is WAITING - one thread waiting inside CacheLoader.load
      // (in startSignal.await()), and the others waiting for that thread's result.
      while (thread.isAlive() && thread.getState() != Thread.State.WAITING) {