src/vs/workbench/browser/parts/editor/editorGroupView.ts/EditorGroupView/focus
class EditorGroupView:	focus(): void {

		// Pass focus to editor panes
		if (this.activeEditorPane) {
			this.activeEditorPane.focus();
		} else {
			this.element.focus();
		}

		// Event
		this._onDidFocus.fire();
	}