defaultPlaceholder(for:with:)
Returns an object that will be used as the placeholder for the binding, when a key value coding compliant property of an instance of the receiving class returns the value specified by marker, and no other placeholder has been specified.
Declaration
class func defaultPlaceholder(for marker: Any?, with binding: NSBindingName) -> Any?Discussion
The marker can be nil or one of the constants described in Selection Markers.