qmlsc/qmllint: optional properties

There are situations in which one wants to access a property of an Item, but you do not know its exact type or you want to use it for different types. For example, using qmllint on qtdeclarative/src/quickcontrols2/material/impl/CheckIndicator.qml yields:

Warning: qtdeclarative/src/quickcontrols2/material/impl/CheckIndicator.qml:19:38: Property "checkState" not found on type "QQuickItem"
    property int checkState: control.checkState
                                     ^^^^^^^^^^

Of course, since control is defined as:

property Item control

and Item does not have a property `checkState`.

However, both ButtonGroup and CheckBox have a property checkState.

If I want to use either of them in a property like this one - with silent qmlsc and no lint warnings - how would you do that?