import org.jetbrains.kotlin.config.ApiVersion
import org.jetbrains.kotlin.config.LanguageFeature
import org.jetbrains.kotlin.config.LanguageVersionSettings
import org.jetbrains.kotlin.contracts.description.EventOccurrencesRange
import org.jetbrains.kotlin.descriptors.ClassKind
import org.jetbrains.kotlin.descriptors.EffectiveVisibility
import org.jetbrains.kotlin.descriptors.Visibility

    return when (this) {
        is KtFe10PsiSymbol<*, *> -> descriptor
        is KtFe10DescSymbol<*> -> descriptor
        is KtFe10DescSyntheticFieldSymbol -> descriptor
        is KtFe10PsiDefaultPropertyGetterSymbol -> descriptor
        is KtFe10PsiDefaultPropertySetterSymbol -> descriptor
        is KtFe10PsiDefaultSetterParameterSymbol -> descriptor
        is KtFe10DescDefaultPropertySetterSymbol -> null

class KtFe10ReceiverParameterSymbol(
    override val descriptor: ReceiverParameterDescriptor,
    override val analysisContext: Fe10AnalysisContext,
) : KtReceiverParameterSymbol(), KtFe10DescSymbol<ReceiverParameterDescriptor> {

    override val type: KtType
        get() = withValidityAssertion {
            descriptor.returnType?.toKtType(analysisContext) ?: error("expect return type for $descriptor")
        }

        val descriptor = getDescriptor<ClassDescriptor>(classSymbol)
            ?: return getEmptyScope()

        return KtFe10ScopeMember(descriptor.unsubstitutedMemberScope, descriptor.constructors, analysisContext)
    }

    override fun getStaticMemberScope(symbol: KtSymbolWithMembers): KtScope {
        val descriptor = getDescriptor<ClassDescriptor>(symbol) ?: return getEmptyScope()

                    else -> {
                        val descriptor = unwrappedType.constructor.declarationDescriptor
                        if (descriptor is TypeParameterDescriptor) {
                            renderTypeParameterType(descriptor, printer)
                        } else if (descriptor is ClassifierDescriptorWithTypeParameters) {

        val subject: KtExpression
        val description: String
        val isCastToNotNull: Boolean
    }

    interface SmartcastImpossibleOnImplicitInvokeReceiver : KtFirDiagnostic<KtExpression> {
        override val diagnosticClass get() = SmartcastImpossibleOnImplicitInvokeReceiver::class
        val desiredType: KtType
        val subject: KtExpression
        val description: String
        val isCastToNotNull: Boolean

        ExpressionExpectedPackageFoundImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.ERROR_IN_CONTRACT_DESCRIPTION) { firDiagnostic ->
        ErrorInContractDescriptionImpl(
            firDiagnostic.a,
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }

        get() = withValidityAssertion {
            ClassId(
                descriptor.functionTypeKind.packageFqName,
                descriptor.functionTypeKind.numberedClassName(descriptor.arity)
            )
        }

    override val classSymbol: KtClassLikeSymbol
        get() = withValidityAssertion { KtFe10DescNamedClassOrObjectSymbol(descriptor, analysisContext) }

    override val ownTypeArguments: List<KtTypeProjection>

        fun KtCall.isInBestCandidates(): Boolean {
            val descriptor = this.safeAs<KtFunctionCall<*>>()?.descriptor as? CallableDescriptor
            return descriptor != null && bestCandidateDescriptors.any { it ->
                DescriptorEquivalenceForOverrides.areCallableDescriptorsEquivalent(
                    it,
                    descriptor,
                    allowCopiesFromTheSameDeclaration = true,