import java.util.stream.Stream;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Supplies an arbitrary "default" instance for a wide range of types, often useful in testing
 * utilities.
 *
 * <p>Covers arrays, enums and common types defined in {@code java.lang}, {@code java.lang.reflect},
 * {@code java.io}, {@code java.nio}, {@code java.math}, {@code java.util}, {@code

public abstract class MultimapBuilder<K0 extends @Nullable Object, V0 extends @Nullable Object> {
  /*
   * Leaving K and V as upper bounds rather than the actual key and value types allows type
   * parameters to be left implicit more often. CacheBuilder uses the same technique.
   */

  private MultimapBuilder() {}

  private static final int DEFAULT_EXPECTED_KEYS = 8;

  /** Uses a hash table to map keys to value collections. */

public abstract class MultimapBuilder<K0 extends @Nullable Object, V0 extends @Nullable Object> {
  /*
   * Leaving K and V as upper bounds rather than the actual key and value types allows type
   * parameters to be left implicit more often. CacheBuilder uses the same technique.
   */

  private MultimapBuilder() {}

  private static final int DEFAULT_EXPECTED_KEYS = 8;

  /** Uses a hash table to map keys to value collections. */

 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, Function, Executor) Futures.transform}, but you will often
 * find it easier to use a framework. Frameworks automate the process, often adding features like
 * monitoring, debugging, and cancellation. Examples of frameworks include:
 *
 * <ul>
 *   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>

   * - Favor responding to interrupts over timeouts.
   * - System.nanoTime() is expensive enough that we want to call it the minimum required number of
   *   times, typically once before invoking a blocking method. This often requires keeping track of
   *   the first time in a method that nanoTime() has been invoked, for which the special value 0L
   *   is reserved to mean "uninitialized". If timeout is non-positive, then nanoTime need never be

   *
   * @param sets the sets to choose elements from, in the order that the elements chosen from those
   *     sets should appear in the resulting lists
   * @param <B> any common base class shared by all axes (often just {@link Object})
   * @return the Cartesian product, as an immutable set containing immutable lists
   * @throws NullPointerException if {@code sets}, any one of the {@code sets}, or any element of a

    alternating: List<Header>,
  ) {
    writer.headers(outFinished, streamId, alternating)
  }

  /**
   * Callers of this method are not thread safe, and sometimes on application threads. Most often,
   * this method will be called to send a buffer worth of data to the peer.
   *
   * Writes are subject to the write window of the stream and the connection. Until there is a

 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

  `Oh, as to the whiting,' said the Mock Turtle, `they--you've
seen them, of course?'

  `Yes,' said Alice, `I've often seen them at dinn--' she
checked herself hastily.

  `I don't know where Dinn may be,' said the Mock Turtle, `but
if you've seen them so often, of course you know what they're
like.'

  `I believe so,' Alice replied thoughtfully.  `They have their

   * name within that type. The constant name should be a sensible identifier that is closest to the
   * "common name" of the media. This is often, but not necessarily the same as the subtype.
   *
   * Be sure to declare all constants with the type and subtype in all lowercase. For types that