FunctionProcessor.kt

override fun visitTypeArgument(typeArgument: KSTypeArgument, data: Unit) {
    ...
    
    val resolvedType: KSType? = typeArgument.type?.resolve()
    file += resolvedType?.declaration?.qualifiedName?.asString() ?: run {
        logger.error("Invalid type argument", typeArgument)
        return
    }
    
    // Generating nested generic parameters if any
    val genericArguments: List<KSTypeArgument> = typeArgument.type?.element?.typeArguments ?: emptyList()
    visitTypeArguments(genericArguments)

    // Handling nullability
    file += if (resolvedType?.nullability == Nullability.NULLABLE) "?" else ""
}