Update PanopticQuality.py

PanopticQuality.py

@@ -113,13 +113,13 @@ class PQMetric(evaluate.Metric):
         self.stuff =  stuff if stuff is not None else DEFAULT_STUFF
         self.per_class = per_class
         self.split_sq_rq = split_sq_rq
-        self.things_stuffs = sorted(self.pq_metric.things) + sorted(self.pq_metric.stuffs)
         self.pq_metric = PanopticQuality(
             things=set([self.label2id[label] for label in self.label2id.keys() if label not in self.stuff]), 
             stuffs=set([self.label2id[label] for label in self.label2id.keys() if label in self.stuff]),
             return_per_class=per_class,
             return_sq_and_rq=split_sq_rq
         )
+        self.things_stuffs = sorted(self.pq_metric.things) + sorted(self.pq_metric.stuffs)
 
     def _info(self):
         return evaluate.MetricInfo(