CGMES export Bug

[AnkurArohi]

Describe the current behavior

When two networks are merged and then the merged network is tried to be exported in CGMES format, this is the exception

java.lang.NullPointerException: null
at com.powsybl.cgmes.conversion.NamingStrategy$Identity.getCgmesId(NamingStrategy.java:72)
at com.powsybl.cgmes.conversion.export.TopologyExport.writeConnectableTerminals(TopologyExport.java:68)
at com.powsybl.cgmes.conversion.export.TopologyExport.writeTerminals(TopologyExport.java:54)
at com.powsybl.cgmes.conversion.export.TopologyExport.write(TopologyExport.java:46)
at com.powsybl.cgmes.conversion.CgmesExport.export(CgmesExport.java:98)
at com.powsybl.iidm.network.Network.write(Network.java:1248)
at com.powsybl.iidm.network.Network.write(Network.java:1269)
at com.powsybl.python.network.NetworkCFunctions.lambda$dumpNetwork$7(NetworkCFunctions.java:185)
at com.powsybl.python.commons.Util.doCatch(Util.java:56)

Describe the expected behavior

There should not be any such exception and if there is such an exception regarding any missing value, the exception should try to mention it

Describe the steps

• Load a DSO network with boundary files
• Load TSO network with boundary files
• Check if the dangling lines df has the boundariesin both DSO and TSO
• Deactivate the DSO voltage levels which are actually duplicates from TSO
• Merge both the networks
• Check the get_lines DF, it should have the dangling lines boundaries merged
• Export to CGMES

Environment

• pypowsybl

Relevant Log Output

No response

Extra Information

No response