Union public struct Union: Fn Union represents the set of resources that are present in at least one of the specified sets. Reference. init(_:) Declaration Swift public init(_ sets: Expr...) Parameters sets Sets of resources to perform the union. © 2018 Fauna, Inc. All rights reserved. (Last updated: 2018-03-21) Generated by jazzy ♪♫ v0.8.2, a Realm project.