IDEWorkbenchPreferencePage breaks ExtenstionFactory

[kerjes]

When extending in plugin.xml

   <extension
         point="org.eclipse.ui.preferencePages">
     <page
            category="mycategory"
            class="org.eclipse.ui.ExtensionFactory:workbenchPreferencePage"
            id="myid"
            name="MyName">
      </page>
    ...

one gets

java.lang.NullPointerException: Cannot invoke "org.eclipse.jface.preference.IntegerFieldEditor.getIntValue()" because "this.saveInterval" is null
  at org.eclipse.ui.internal.dialogs.WorkbenchPreferencePage.performOk(WorkbenchPreferencePage.java:447)
  at org.eclipse.jface.preference.PreferencePage.performApply(PreferencePage.java:457)
  at org.eclipse.jface.preference.PreferencePage.lambda$1(PreferencePage.java:289)

because

eclipse.platform.ui/bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/dialogs/WorkbenchPreferencePage.java

Line 447 in 7aaa014

store.setValue(IPreferenceConstants.WORKBENCH_SAVE_INTERVAL, saveInterval.getIntValue());

is initiated by

eclipse.platform.ui/bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/dialogs/WorkbenchPreferencePage.java

Line 219 in 7aaa014

protected void createSaveIntervalGroup(Composite composite) {

and only called from

eclipse.platform.ui/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/IDEWorkbenchPreferencePage.java

Line 45 in 7aaa014

createSaveIntervalGroup(composite);

and ExtensionFactory does only initiate WorkbenchPreferencePage

https://github.com/eclipse-platform/eclipse.platform.ui/blob/7aaa014a1d1053e012f2bc0b50eddff30cb2b50c/bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/ExtensionFactory.java#L182C1-L184C4

[jukzi]

please propose a solution where either a) "saveInterval" is tagged mandatory and if missing an appropriate error message appears or b) define appropriate default value that is used and document it.