src/vs/workbench/browser/parts/editor/editorPart.ts/EditorPart/addGroup
class EditorPart:	addGroup(location: IEditorGroupView | GroupIdentifier, direction: GroupDirection, options?: IAddGroupOptions): IEditorGroupView {
		const locationView = this.assertGroupView(location);

		const group = this.doAddGroup(locationView, direction);

		if (options?.activate) {
			this.doSetGroupActive(group);
		}

		return group;
	}