exceptions in a class of assets

sir if there is a class of assets that is measured at revaluation model, but there is this one asset ( or say, group of assets within that class) which cannot be measured at revaluation model because there is no active market for it, then is it measured at cost model while rest of the assets within that class continue to be measured at revaluation model? Or that all assets within that class will now have be measured at revelation model?