Returns a predicate that matches any object whose metadata contains the provided key.
- iOS 8.0+
- watchOS 2.0+
The metadata key to match. For a list of preset keys, see Metadata Keys. You may also search for custom keys.
A predicate that matches any object whose metadata contains the provided key.
Use this convenience method to create a predicate that finds all objects with a specific key stored in their metadata. The following sample uses both the convenience method and a predicate format string to create equivalent predicates.