Support for version spec in requires & arbitrary mismatching depths across folders (#37854)

* Support for version spec in requires & arbitrary mismatching depths

* Quality

* Testing

tests/utils/import_structures/import_structure_raw_register_with_versions.py

@@ -0,0 +1,92 @@
+# Copyright 2024 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# fmt: off
+
+from transformers.utils.import_utils import requires
+
+
+@requires(backends=("torch>=2.5",))
+class D0:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch>=2.5",))
+def d0():
+    pass
+
+
+@requires(backends=("torch>2.5",))
+class D1:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch>2.5",))
+def d1():
+    pass
+
+
+@requires(backends=("torch<=2.5",))
+class D2:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch<=2.5",))
+def d2():
+    pass
+
+@requires(backends=("torch<2.5",))
+class D3:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch<2.5",))
+def d3():
+    pass
+
+
+@requires(backends=("torch==2.5",))
+class D4:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch==2.5",))
+def d4():
+    pass
+
+
+@requires(backends=("torch!=2.5",))
+class D5:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch!=2.5",))
+def d5():
+    pass
+
+@requires(backends=("torch>=2.5", "accelerate<0.20"))
+class D6:
+    def __init__(self):
+        pass
+
+
+@requires(backends=("torch>=2.5", "accelerate<0.20"))
+def d6():
+    pass