private
typealias AsyncModelRequest = Pair<KotlinBuildScriptModelRequest, Continuation<KotlinBuildScriptModel?>>


internal
open class KotlinBuildScriptModelRepository {

    open suspend fun scriptModelFor(request: KotlinBuildScriptModelRequest): KotlinBuildScriptModel? =
        suspendCoroutine { k ->
            accept(request, k)
            processor.poke()
        }

    protected

        fun newModelRequest() = KotlinBuildScriptModelRequest(projectDir, scriptFile)

        fun asyncResponseTo(request: KotlinBuildScriptModelRequest): Deferred<KotlinBuildScriptModel?> = async {
            subject.scriptModelFor(request)
        }

        // when:
        val pendingTasks =
            (0..2).map { index ->
                val request = newModelRequest()
                request to asyncResponseTo(request).also {

        val request = scriptModelRequestFrom(scriptFile, environment, cid)
        log(SubmittedModelRequest(cid, scriptFile, request))

        val response = DefaultKotlinBuildScriptModelRepository.scriptModelFor(request)
        if (response == null) {
            log(RequestCancelled(cid, scriptFile, request))
            return null
        }
        log(ReceivedModelResponse(cid, scriptFile, response))