* @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public abstract class Ordering<T extends @Nullable Object> implements Comparator<T> {
  // Natural order

  /**
   * Returns a serializable ordering that uses the natural order of the values. The ordering throws
   * a {@link NullPointerException} when passed a null parameter.
   *

  /**
   * Returns an unmodifiable <b>view</b> of the union of two sets. The returned set contains all
   * elements that are contained in either backing set. Iterating over the returned set iterates
   * first over all the elements of {@code set1}, then over each element of {@code set2}, in order,
   * that is not contained in {@code set1}.
   *
   * <p>Results are undefined if {@code set1} and {@code set2} are sets based on different

   * until a nonzero result is found; imposes "dictionary order." If the end of one iterable is
   * reached, but not the other, the shorter iterable is considered to be less than the longer one.
   * For example, a lexicographical natural ordering over integers considers {@code [] < [1] < [1,
   * 1] < [1, 2] < [2]}.
   *

   * this range map are guaranteed to read through to the returned {@code Map}.
   *
   * <p>The returned {@code Map} iterates over entries in ascending order of the bounds of the
   * {@code Range} entries.
   *
   * <p>It is guaranteed that no empty ranges will be in the returned {@code Map}.
   */
  Map<Range<K>, V> asMapOfRanges();

  /**

    version number is enough for some build systems (notably, Gradle) to select
    that empty artifact over the "real" listenablefuture-1.0 -- avoiding a
    conflict with the copy of ListenableFuture in guava itself. If users are
    using an older version of Guava or a build system other than Gradle, they
    may see class conflicts. If so, they can solve them by manually excluding

 *     with lexical order (case-insensitive in the English locale).
 *     <code>ga</code> and <code>final</code> sort the same as not having a qualifier.
 *   </li>
 * <li>A hyphen usually precedes a qualifier, and is always less important than digits/number. For example
 *   {@code 1.0.RC2 < 1.0-RC3 < 1.0.1}; but prefer {@code 1.0.0-RC2} over {@code 1.0.0.RC2}, and more

   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableSet}. Elements appear in the resulting set in the encounter order of the stream; if
   * the stream contains duplicates (according to {@link Object#equals(Object)}), only the first
   * duplicate in encounter order will appear in the result.
   *
   * @since 21.0
   */
  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {

   * Creates a new min-max priority queue with default settings: natural order, no maximum size, no
   * initial contents, and an initial expected size of 11.
   */
  public static <E extends Comparable<E>> MinMaxPriorityQueue<E> create() {
    return new Builder<Comparable<E>>(Ordering.natural()).create();
  }

  /**
   * Creates a new min-max priority queue using natural order, no maximum size, and initially
   * containing the given elements.

    client ->> dep_req: Start request
    Note over dep_req: Run code up to yield
    dep_req ->> dep_func: Pass dependency
    Note over dep_func: Run code up to yield
    dep_func ->> operation: Run path operation with dependency
    operation ->> dep_func: Return from path operation
    Note over dep_func: Run code after yield
    Note over dep_func: ✅ Dependency closed
    dep_func ->> client: Send response to client

//     only after as a 2-phase call, allowing the older dataDir to
//     hang-around in-case we need some form of recovery.
type RenameDataResp struct {
	Sign       []byte `msg:"s"`
	OldDataDir string `msg:"od"` // contains '<uuid>', it is designed to be passed as value to Delete(bucket, pathJoin(object, dataDir))
}

const (
	checkPartUnknown int = iota

	// Changing the order can cause a data loss