type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v
}

// GetNonBlocking will return the singleton value or nil if not set yet.

	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}
	} else {
		req.Trailer = nil
	}
	return &s3ChunkedReader{

        final ProjectBuildList byTaskSegment = projectBuildList.getByTaskSegment(taskSegment);
        assertEquals(projectBuildList.size(), byTaskSegment.size()); // TODO Make multiple segments on projectBuildList
    }

    write(out, data, 0, 100, true);
    File file = out.getFile();
    assertEquals(100, file.length());
    assertTrue(file.exists());
    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override

		if err != nil {
			return nil, fmt.Errorf("metacacheWriter: unable to create writer: %w", err)
		}
		if w.mw == nil {
			return nil, errors.New("metacacheWriter: writer not initialized")
		}
	}
	objs := make(chan metaCacheEntry, 100)
	w.streamErr = nil
	w.streamWg.Add(1)
	go func() {
		defer w.streamWg.Done()
		for o := range objs {
			if len(o.name) == 0 || w.streamErr != nil {
				continue
			}

			if err != nil {
				err = msgp.WrapError(err, "Results")
				return
			}
			if cap(z.Results) >= int(zb0002) {
				z.Results = (z.Results)[:zb0002]
			} else {
				z.Results = make([]int, zb0002)
			}
			for za0001 := range z.Results {
				z.Results[za0001], err = dc.ReadInt()
				if err != nil {
					err = msgp.WrapError(err, "Results", za0001)
					return
				}
			}
		default:

package pubsub

import (
	"bytes"
	"encoding/json"
	"fmt"
	"sync"
	"sync/atomic"
)

// GetByteBuffer returns a byte buffer from the pool.
var GetByteBuffer = func() []byte {
	return make([]byte, 0, 4096)
}

// Sub - subscriber entity.
type Sub[T Maskable] struct {
	ch     chan T
	types  Mask
	filter func(entry T) bool
}

// PubSub holds publishers and subscribers

	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the
	// allocated slice, but this pattern causes b to escape onto the heap.
	//
	// Instead use the append-make pattern with a nil slice to ensure that

 *
 * <p>To force selection of our fallback strategies, we load {@link AbstractFuture} (and all of
 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain
 * platform classes unavailable. Then we construct a test suite so we can run the normal
 * AbstractFutureTest test methods in these degenerate classloaders.
 */

@NullUnmarked

          latch2.countDown()
        }
      }
    val request2Listener: EventListener =
      object : EventListener() {
        override fun connectStart(
          call: Call,
          inetSocketAddress: InetSocketAddress,
          proxy: Proxy,
        ) {
          // Let request1 proceed to make a connection.
          latch1.countDown()