Harbor Studio, a fictional production team, needs collection utilities for its planning board. Some utilities select a portion of an ordered list; others merge settings or look up the latest label for an identifier. You have already learned each operation. The task is to choose it correctly when the input shape changes. Keep the original list when a task asks for a copy, retain duplicate quantities when sorting, and distinguish an absent setting from an empty one. The examples use fresh labels and values. A function that follows the rule should work for every batch, including a batch with no rows.