src/vs/workbench/browser/layout.ts/Layout/getLayoutClasses
class Layout:	getLayoutClasses(): string[] {
		return coalesce([
			this.state.sideBar.hidden ? Classes.SIDEBAR_HIDDEN : undefined,
			this.state.editor.hidden ? Classes.EDITOR_HIDDEN : undefined,
			this.state.panel.hidden ? Classes.PANEL_HIDDEN : undefined,
			this.state.statusBar.hidden ? Classes.STATUSBAR_HIDDEN : undefined,
			this.state.fullscreen ? Classes.FULLSCREEN : undefined
		]);
	}