classShortenStrategy: (KtClassLikeSymbol) -> ShortenStrategy,
        callableShortenStrategy: (KtCallableSymbol) -> ShortenStrategy,
    ): ShortenCommand {
        // Compiler implementation does nothing.
        // Descriptor-based shortening is implemented on the IDE plugin side.
        val ktFilePointer = SmartPointerManager.createPointer(file)

        return object : ShortenCommand {

    override val UNIT: KtType
        get() = withValidityAssertion { analysisContext.builtIns.unitType.toKtType(analysisContext) }

    override val NOTHING: KtType
        get() = withValidityAssertion { analysisContext.builtIns.nothingType.toKtType(analysisContext) }

    override val ANY: KtType

    override val NOTHING: KtType by cachedBuiltin(builtinTypes.nothingType)
    override val ANY: KtType by cachedBuiltin(builtinTypes.anyType)

    override val THROWABLE: KtType by cachedBuiltin(builtinTypes.throwableType)
    override val NULLABLE_ANY: KtType by cachedBuiltin(builtinTypes.nullableAnyType)
    override val NULLABLE_NOTHING: KtType by cachedBuiltin(builtinTypes.nullableNothingType)

            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.IMPLICIT_NOTHING_RETURN_TYPE) { firDiagnostic ->
        ImplicitNothingReturnTypeImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.IMPLICIT_NOTHING_PROPERTY_TYPE) { firDiagnostic ->
        ImplicitNothingPropertyTypeImpl(
            firDiagnostic as KtPsiDiagnostic,

- [`KT-38288`](https://youtrack.jetbrains.com/issue/KT-38288) Unresolved reference for type parameter upper bound of nested class when outer class extends it with star projected type argument
- [`KT-37490`](https://youtrack.jetbrains.com/issue/KT-37490) NULL_FOR_NONNULL_TYPE: "Null can not be a value of a non-null type Nothing" when null is passed to nullable argument of type projected method

    companion object {
        private fun throwUnexpectedElementError(element: FirBasedSymbol<*>): Nothing {
            errorWithAttachment("Unexpected ${element::class.simpleName}") {
                withFirSymbolEntry("firSymbol", element)
            }
        }

        private fun throwUnexpectedElementError(element: FirElement): Nothing {
            errorWithAttachment("Unexpected ${element::class.simpleName}") {

                false

            /**
             * EXPRESSIONS
             */
            // A handful of expression are never considered used:

            //  - Everything of type `Nothing`
            is KtThrowExpression ->
                false
            is KtReturnExpression ->
                false
            is KtBreakExpression ->
                false
            is KtContinueExpression ->