runToCompletion {
        writeOperation()
    }


/**
 * [Starts][startCoroutine] the suspending [block], asserts it runs
 * to completion and returns its result.
 */
private
fun <R> runToCompletion(block: suspend () -> R): R {
    var completion: Result<R>? = null
    block.startCoroutine(
        Continuation(EmptyCoroutineContext) {
            completion = it
        }
    )

import java.io.ObjectInputStream
import java.io.ObjectOutputStream
import kotlin.coroutines.Continuation
import kotlin.coroutines.CoroutineContext
import kotlin.coroutines.coroutineContext
import kotlin.coroutines.startCoroutine
import kotlin.coroutines.suspendCoroutine


fun <T> singleton(value: T): Codec<T> =
    SingletonCodec(value)


fun <T> codec(
    encode: suspend WriteContext.(T) -> Unit,

	// deterministic and because there is no real work anyway.
	par := cfg.BuildP
	if cfg.BuildN {
		par = 1
	}
	for i := 0; i < par; i++ {
		wg.Add(1)
		go func() {
			ctx := trace.StartGoroutine(ctx)
			defer wg.Done()
			for {
				select {
				case _, ok := <-b.readySema:
					if !ok {
						return
					}
					// Receiving a value from b.readySema entitles