VoidItem is always enabled if it does not have `Optional=true' defined in the sbt file
To reproduce the bug: Add below line to any operator sbt file:
<Void Name="test" Label="test" NumberOfRequiredValues="1" AdvanceLevel = "1" Option = "true" IsEnabledByDefault = "true">
And try to find this void item in the operator source file. No matter user checks it in the operator panel or not, it's always shown as enabled. After adding
Optional=true, it works fine.