Purpose

This should have been included w/ PR-8131. I realized the bug when testing D4R UI node deserilazation in the current task.

If a selection node is added to the graph with no selection that graph would serialize the InstanceID property as null. This would cause the node to not deserialization properly due to the missing property and it would never be added to the graph when reopening. This PR initializes InstanceID w/ an empty list to avoid the null value.

I also verified all the RTF selection tests still pass with this change but we may want to add additional testing to catch this behavior in the future.

To reproduce:

• add a selection node to the graph (without selecting anything)
• save and close the graph
• reopen and verify the node is missing

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning, and are documented in the API Changes document.

Reviewers

@mjkkirschner @QilongTang

FYIs

@smangarole