FIX: Add error message if extension is started with an empty HFSS 3D Layout design #6822
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This PR provides a fix for #6780 by introducing an error message in case the cutout extension is started on an empty HFSS 3D Layout design.
This case is not supported by the
__load_objects_net()method (which is part of the__init__()of the extension) responsible for loading the objects by net from the EDB modeler: Therefore an error is now raised to avoid subsequent crash of the code in this situation.A corresponding unit test is added.
Close #6780.