 public class SwiftData {
     let filename: String
 
-    /// Used for testing.
     static var EnableWAL = true
+    static var EnableForeignKeys = true
 
     /// Used for testing.
     static var ReuseConnections = true

        statement = nil
        super.close()
    }
}
        if SwiftData.EnableWAL {
            let cursor = executeQueryUnsafe("PRAGMA journal_mode=WAL", factory: StringFactory)
            assert(cursor[0] as! String == "wal", "WAL journal mode set")
        }

        if SwiftData.EnableForeignKeys {
            let cursor = executeQueryUnsafe("PRAGMA foreign_keys=ON", factory: IntFactory)
        }

        // Retry queries before returning locked errors.
