*/
    private fun KaSession.canBeReferencedAsExtensionOn(symbol: KaCallableSymbol, actualReceiverType: KaType): Boolean {
        val extensionReceiverType = symbol.receiverParameter?.type ?: return false
        return isPossiblySuperTypeOf(extensionReceiverType, actualReceiverType)
    }

    /**
     * Same constraints as in [canBeReferencedAsExtensionOn].
     *