Google CALDAV ignoring filter options - calendar

Question

Is there any documentation why does the google caldav api ignores this request.
<?xml version="1.0" encoding="UTF-8"?>
<C:calendar-query xmlns:d="DAV:"
xmlns:C="urn:ietf:params:xml:ns:caldav"
xmlns:A="http:/ /apple.com/ns/ical/">
<d:prop>
<d:getetag/>
<C:calendar-data/>
</d:prop>
<C:filter>
<C:comp-filter name="VCALENDAR">
<C:comp-filter name="VEVENT">
<C:prop-filter name="UID">
<C:text-match collation="i;octet">xxxxxxxxxxxx</C:text-match>
</C:prop-filter>
</C:comp-filter>
</C:comp-filter>
</C:filter>
</C:calendar-query>
It returns every event but it should return only the one i requested in the filter.
I can only filter the events with
<C:time-range start="20160326T230000Z" end="20160430T220000Z"/>
but everything else is just ignored.

Answer 1

I find another solution to get only one event by uid with caldav api google.
I use href url of the event like $href="https://apidata.googleusercontent.com/caldav/v2/IDCalendar/events/**uid.**ics
And i query with :
<?xml version="1.0" encoding="utf-8" ?>
<C:calendar-multiget xmlns="DAV:"mlns:C="urn:ietf:params:xml:ns:caldav">
<prop><getetag/><C:calendar-data/></prop>
<href>$href</href>
</C:calendar-multiget>
and i get only the event with UID :) .
Dam

Answer 2

but Google CalDAV supports calendar-multiget, where you can use same url pattern
https://icalendar.org/CalDAV-Access-RFC-4791/7-9-caldav-calendar-multiget-report.html
Example:
<?xml version='1.0' encoding='utf-8'?>
<C:calendar-multiget xmlns:C="urn:ietf:params:xml:ns:caldav" xmlns:CS="http://calendarserver.org/ns/" xmlns:D="DAV" xmlns:I="http://apple.com/ns/ical/">
<ns0:prop xmlns:ns0="DAV:">
<ns0:getetag/>
<C:calendar-data/>
</ns0:prop>
<ns0:href xmlns:ns0="DAV:">/caldav/v2/[calendar_id]/events/[UID]</ns0:href>
</C:calendar-multiget>
with response
<?xml version="1.0" encoding="UTF-8"?>
<D:multistatus xmlns:D="DAV:" xmlns:caldav="urn:ietf:params:xml:ns:caldav" xmlns:cs="http://calendarserver.org/ns/" xmlns:ical="http://apple.com/ns/ical/">
<D:response xmlns:carddav="urn:ietf:params:xml:ns:carddav" xmlns:cm="http://cal.me.com/_namespace/" xmlns:md="urn:mobileme:davservices">
<D:href>/caldav/v2/[calendarID]/events/[UID]</D:href>
<D:propstat>
<D:status>HTTP/1.1 200 OK</D:status>
<D:prop>
<D:getetag>"63701474571"</D:getetag>
<caldav:calendar-data>BEGIN:VCALENDAR
.....
</caldav:calendar-data>
</D:prop>
</D:propstat>
</D:response>
</D:multistatus>