ComboBox select first item kotlin

General
1

I have code in java which wors pretty well: public static void selectFirst(ComboBox combo) { DataProvider dataProvider = combo.getDataProvider(); if (dataProvider != null) { Optional comboValues = dataProvider.fetch(new Query<>()).findFirst(); if (comboValues.isPresent()) { combo.setValue(comboValues.get()); } } } I tried to convert to this method to kotlin and this is what IJ Idea generated

fun selectFirst(combo: ComboBox<*>) { val dataProvider = combo.dataProvider if (dataProvider != null) { val comboValues = dataProvider.fetch(Query<Any, Any>()).findFirst() if (comboValues.isPresent) { combo.setValue(comboValues.get()) } } } But it won’t compile. This is what compiler says:

Out-projected type 'DataProvider<out Any!, out Any!>!' prohibits the use of 'public abstract fun fetch(p0: Query<T!, F!>!): Stream<T!>! defined in com.vaadin.data.provider.DataProvider' How can this kotlin code be fixed?
Or is there any other way of selecting first item in combobox which can be converted to kotlin?

2

Well this seems to work:

fun selectFirst(combo: ComboBox<*>) {
  @Suppress("UNCHECKED_CAST") val dataProvider = combo.dataProvider as DataProvider<Any, Any>
  val comboValues = dataProvider.fetch(Query<Any, Any>()).findFirst() 
 if (comboValues.isPresent) { 
   combo.value = comboValues.get() 
 }
}