Retrieving a list of collections

To retrieve collections with informations about Jingle call events item-type attribute needs to be added to <list/> element from section 7.1 Retrieving a List of Collections of XEP-0136 specification with value set to call.

A result it will be returned as specified in XEP-0136, but <list/> element will contain <events/> element for each collections instead of <chat/> element. Additionally <list/> element will have item-type attribute set to call.