src/vs/workbench/services/history/browser/historyService.ts/EditorNavigationStack/onWillMoveEditor
class EditorNavigationStack:	private onWillMoveEditor(e: IEditorWillMoveEvent): void {
		this.trace('onWillMoveEditor()', e.editor);

		if (this.scope === GoScope.EDITOR_GROUP) {
			return; // ignore move events if our scope is group based
		}

		for (const entry of this.stack) {
			if (entry.groupId !== e.groupId) {
				continue; // not in the group that reported the event
			}

			if (!this.editorHelper.matchesEditor(e.editor, entry.editor)) {
				continue; // not the editor this event is about
			}

			// Update to target group
			entry.groupId = e.target;
		}
	}