``` data class Custom val i Int typealias MyData = Map lt Cu kotlinlang #announcements

``` data class Custom(val i: Int) typealias MyDat...

okkero

03/07/2017, 12:27 PM

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data class Custom(val i: Int)

typealias MyData = Map<Custom, List<Int>>

fun MyData.isEmpty(key: Custom) = this[key]?.isEmpty()