How to set the extent of the current window

First we find the instance of GtWorldElement GtWorldTabElement subclass: #GtWorldElement instanceVariableNames: 'spotterDropdown subSpaceDropdown notificationsDropdown announcer' classVariableNames: 'IsWorldSpotterPreviewDisplayed WorldSpotterSize' package: 'GToolkit-World-UI' based on the name of the current page:

currentWorldElement := GtWorldElement allInstances
		detect: [ :eachWorld | 
			eachWorld tabs tabs
				anySatisfy: [ :each | 
					each isSelected
						and: [ each children first text asString beginsWith: 'How to set' ] ] ]
  

Once we have the world element, we set the extent:

currentWorldElement space extent: 1600@1000.