abstract fun addAll(elements: Collection<E>): Boolean

Adds all of the elements in 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.

abstract fun addAll(
    index: Int, 
    elements: Collection<E>
): Boolean

Inserts all of the elements in the specified collection elements into this list at the specified index.

Return true if the list was changed as the result of the operation.