interface Host {

        fun cachedClassFor(
            programId: ProgramId
        ): CompiledScript?

        fun cache(
            specializedProgram: CompiledScript,
            programId: ProgramId
        )

        fun cachedDirFor(
            scriptHost: KotlinScriptHost<*>,
            programId: ProgramId,
            compilationClassPath: ClassPath,
            accessorsClassPath: ClassPath,

            )
        }

        override fun cachedClassFor(
            programId: ProgramId
        ): CompiledScript? = classloadingCache.get(programId)

        override fun cache(
            specializedProgram: CompiledScript,
            programId: ProgramId
        ) {
            classloadingCache.put(
                programId,
                specializedProgram
            )
        }

        val programHost = safeMockProgramHost {
            on { accessorsClassPathFor(scriptHost) } doReturn accessorsClassPath
        }

        val scriptTemplateId = "Project/TopLevel/stage2"
        val programId = ProgramId(scriptTemplateId, sourceHash, mock())

        private
        fun verifyStandardOutput(program: ExecutableProgram) {
            assertStandardOutputOf(expectedStage1Output) {

        Type.getType(ProgramId::class.java),
        Type.getType(ClassPath::class.java)
    )

    private
    val compileSecondStageOfDescriptor = Type.getMethodDescriptor(
        Type.getType(CompiledScript::class.java),
        stagedProgram,
        Type.getType(KotlinScriptHost::class.java),
        Type.getType(ProgramId::class.java),
        Type.getType(ProgramKind::class.java),