Instantiates and returns a source query.
- iOS 8.0+
- Mac Catalyst 13.0+
- watchOS 2.0+
A predicate that limits the samples matched by the query. Pass
nilif you want to receive the sources for all the samples of the specified type.
A block that is called when the query finishes executing. This block takes the following parameters:
A reference to the query calling this block.
A set containing the sources for all the samples that match both the sample type and the object predicate, or
nilif an error occurred.
If an error occurs, this parameter contains an object describing the error; otherwise, it is
A newly initialized sample query object.