* across calls to multiple listeners. Specifically, a given listener will have its callbacks
   * invoked in the same order as the underlying service enters those states. Additionally, at most
   * one of the listener's callbacks will execute at once. However, multiple listeners' callbacks
   * may execute concurrently, and listeners may execute in an order different from the one in which

/// tip

If you are already using **FastAPI** version **0.99.0 or above**, you can probably **skip** these details.

They are more relevant for older versions, before OpenAPI 3.1.0 was available.

You can consider this a brief OpenAPI and JSON Schema **history lesson**. 🤓

///

/// warning

These are very technical details about the standards **JSON Schema** and **OpenAPI**.

/**
 * A certificate and its private key. These are some properties of certificates that are used with
 * TLS:
 *
 *  * **A common name.** This is a string identifier for the certificate. It usually describes the
 *    purpose of the certificate like "Entrust Root Certification Authority - G2" or
 *    "www.squareup.com".
 *
 *  * **A set of hostnames.** These are in the certificate's subject alternative name (SAN)

 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PairedStatsAccumulator {

  // These fields must satisfy the requirements of PairedStats' constructor as well as those of the
  // stat methods of this class.
  private final StatsAccumulator xStats = new StatsAccumulator();
  private final StatsAccumulator yStats = new StatsAccumulator();

  // set by the controller component of the resource driver whose name
  // matches the DriverName set in the ResourceClaimStatus this
  // ResourceHandle is embedded in. It is set at allocation time and is
  // intended for processing by the kubelet plugin whose name matches
  // the DriverName set in this ResourceHandle.
  //

   *   <li>When the RateLimiter is not used, this goes right (up to maxPermits)
   *   <li>When the RateLimiter is used, this goes left (down to zero), since if we have
   *       storedPermits, we serve from those first
   *   <li>When _unused_, we go right at a constant rate! The rate at which we move to the right is
   *       chosen as maxPermits / warmupPeriod. This ensures that the time it takes to go from 0 to

  public static <R, C, V> Builder<R, C, V> builder() {
    return new Builder<>();
  }

  /**
   * Verifies that {@code rowKey}, {@code columnKey} and {@code value} are non-null, and returns a
   * new entry with those values.
   */
  static <R, C, V> Cell<R, C, V> cellOf(R rowKey, C columnKey, V value) {
    return immutableCell(
        checkNotNull(rowKey, "rowKey"),
        checkNotNull(columnKey, "columnKey"),

  // that should be running the daemon pod (i.e. status.desiredNumberScheduled)
  // can have their pods stopped for an update at any given time. The update
  // starts by stopping at most 30% of those DaemonSet pods and then brings
  // up new DaemonSet pods in their place. Once the new pods are available,
  // it then proceeds onto other DaemonSet pods, thus ensuring that at least

     * (i.e. seconds since Epoch 1970). Times should be the same as those
     * reported using the properties dialog of the Windows Explorer program.
     *
     * For Win95/98/Me this is actually the last write time. It is currently
     * not possible to retrieve the create time from files on these systems.
     *
     * @return The number of milliseconds since the 00:00:00 GMT, January 1,

    return builder.buildKeepingLast();
  }

  /**
   * Returns a map with the given {@code values}, indexed by keys derived from those values. In
   * other words, each input value produces an entry in the map whose key is the result of applying
   * {@code keyFunction} to that value. These entries appear in the same order as the input values.
   * Example usage:
   *
   * <pre>{@code