message: Bugfix: return undefined on empty opList
diff: @@ -872,10 +872,8 @@ export class Client {
  }
  }
  - if (opList.length === 1) {
  - return opList[0];
  - } else {
  - return OpBuilder.createGroupOp(...opList);
  + if (opList.length > 0) {
  + return opList.length === 1 ? opList[0] : OpBuilder.createGroupOp(...opList);
  }
  }
  