Occasional NPE on start-up setting focus in ResourceNavigator

java.lang.NullPointerException
at org.eclipse.ui.views.navigator.ResourceNavigator.setFocus(ResourceNavigator.java:1273)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.delegateSetFocus(CompatibilityPart.java:191)

Assuming this is getting through Eclipse event handling before explorer is finished creating control. Should be able to override setFocus() in ModelResourceNavigator and check for null UI components.