* It is set by a client who only wants to make a request if it can be fully satisfied by the
   * cache. Cached responses that would require validation (ie. conditional gets) are not permitted
   * if this header is set.
   */
  @get:JvmName("onlyIfCached") val onlyIfCached: Boolean,
  @get:JvmName("noTransform") val noTransform: Boolean,
  @get:JvmName("immutable") val immutable: Boolean,