[1.30.x] How to enable ODataMessageParser?

Hi,

as per https://openui5.hana.ondemand.com/#docs/guide/81c735e69d354de98b0bd139e4bd4e10.html : "

The v2.ODataModel supports automatic parsing of server messages by means of sap.ui.model.odata.ODataMessageParser"

How do I enable this? I have useBatch: true and a batch with a server error but sap.ui.getCore().getMessageManager().getMessageModel() is still empty.

Also what is the recommended way to show the message count on a button like in https://openui5.hana.ondemand.com/explored.html#/sample/sap.m.sample.MessagePopover/code with sap.ui.getCore().getMessageManager().getMessageModel() ?

Thanks in advance for any hints,

Wolfgang