) : KaSubstitutorFactory(), KaFirSessionComponent {

    override fun buildSubstitutor(builder: KaSubstitutorBuilder): KaSubstitutor {
        if (builder.mappings.isEmpty()) return KaSubstitutor.Empty(token)

        val firSubstitution = buildMap {
            builder.mappings.forEach { (ktTypeParameterSymbol, ktType) ->
                check(ktTypeParameterSymbol is KaFirTypeParameterSymbol)
                check(ktType is KaFirType)