Retrieve a list of entries from collection

To retrieve items with informations about Jingle call from collection item-type attribute needs to be added to <retrieve/> element from section 7.2 Retrieving a Collection of XEP-0136 specification with value set to call.

A result will be returned as specified in XEP-0136, but instead of <chat/> element <events/> element will be returned. Moreover instead of message subelements in <from/> and <to/> elements, there will be custom element containing information about call, ie. Jingle session ID - <sid/>.