* @throws SmbException
     */
    synchronized SmbFileHandleImpl ensureOpen () throws CIFSException {
        // ensure file is open
        if ( this.handle == null || !this.handle.isValid() ) {
            // one extra acquire to keep this open till the stream is released
            this.handle = this.file.openUnshared(this.openFlags, this.access, this.sharing, SmbConstants.ATTR_NORMAL, this.options).acquire();
            return this.handle;

  /** The HTTP {@code If-Modified-Since} header field name. */
  public static final String IF_MODIFIED_SINCE = "If-Modified-Since";
  /** The HTTP {@code If-None-Match} header field name. */
  public static final String IF_NONE_MATCH = "If-None-Match";
  /** The HTTP {@code If-Range} header field name. */
  public static final String IF_RANGE = "If-Range";
  /** The HTTP {@code If-Unmodified-Since} header field name. */

* Add perma-failed deployments API ([#19343](https://github.com/kubernetes/kubernetes/pull/19343), [@kargakis](https://github.com/kargakis))

### Other notable changes

* Federation: allow specification of dns zone by ID ([#36336](https://github.com/kubernetes/kubernetes/pull/36336), [@justinsb](https://github.com/justinsb))

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