next
TypeScriptnext(): Promise<(HKWorkoutEffortRelationshipQueryDescriptor_Result) | null>Swift declarationmutating func next() async throws -> HKWorkoutEffortRelationshipQueryDescriptor.Results.Element?Asynchronously advances to the next element and returns it, or ends the sequence if there is no next element. - Returns: The next element, if it exists, or `nil` to signal the end of the sequence.