Update formatting.py (#10743)

Author: captainIT

mmdet/datasets/transforms/formatting.py

@@ -133,10 +133,8 @@ def transform(self, results: dict) -> dict:
 
         img_meta = {}
         for key in self.meta_keys:
-            assert key in results, f'`{key}` is not found in `results`, ' \
-                f'the valid keys are {list(results)}.'
-            img_meta[key] = results[key]
-
+            if key in results:
+                img_meta[key] = results[key]
         data_sample.set_metainfo(img_meta)
         packed_results['data_samples'] = data_sample