[Core] opset ver. fallback for ModelWrapper.get_customop_wrapper

Author: maltanar

src/qonnx/core/modelwrapper.py

@@ -743,9 +743,19 @@ def get_opset_imports(self):
         """Returns a list of imported opsets as a {domain, version} dictionary."""
         return {opset.domain: opset.version for opset in self._model_proto.opset_import}
 
-    def get_customop_wrapper(self, node):
+    def get_customop_wrapper(self, node, fallback_customop_version=1):
         """Return CustomOp instance for given node, respecting the
-        imported opset version in the model protobuf."""
+        imported opset version in the model protobuf. If the node's domain
+        is not found in the model's opset imports, fallback_customop_version
+        will be used."""
         opset_imports = self.get_opset_imports()
-        opset_import = opset_imports[node.domain]
-        return getCustomOp(node, onnx_opset_version=opset_import)
+        try:
+            opset_import = opset_imports[node.domain]
+            return getCustomOp(node, onnx_opset_version=opset_import)
+        except KeyError:
+            # domain not found in imports, use fallback version
+            warnings.warn(
+                f"Domain {node.domain} not found in model opset imports, "
+                f"using fallback_customop_version={fallback_customop_version}"
+            )
+            return getCustomOp(node, onnx_opset_version=fallback_customop_version)