kotlin-stdlib / kotlin.reflect / KMutableProperty2 / Setter Setter JVM 1.0 interface Setter < D , E , V > : KMutableProperty.Setter < V > , ( D , E , V ) -> Unit (source) Setter of the property is a set method declared alongside the property. Can be used as a function that takes an argument of type D (the first receiver), an argument of type E (the second receiver), and the new property value and returns Unit .