abstract fun addAll(elements: Collection<E>): Boolean
Adds all of the elements of the specified collection to this collection.
Return true if any of the specified elements was added to the collection, false if the collection was not modified.
© 2010–2020 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-mutable-collection/add-all.html