chore: import upstream snapshot with attribution

decoding/GAD/fairseq/data/sort_dataset.py

@@ -0,0 +1,21 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+import numpy as np
+
+from . import BaseWrapperDataset
+
+
+class SortDataset(BaseWrapperDataset):
+    def __init__(self, dataset, sort_order):
+        super().__init__(dataset)
+        if not isinstance(sort_order, (list, tuple)):
+            sort_order = [sort_order]
+        self.sort_order = sort_order
+
+        assert all(len(so) == len(dataset) for so in sort_order)
+
+    def ordered_indices(self):
+        return np.lexsort(self.sort_order)