Issues PROPPATCH request on the provided uri, or, in case it's null, on the URI defined in
associated Source, with the changes.
The order of requested changes inside xml is significant, unlike on other places.
| this | |
| uri |
URI to issue the request for, or null to read from Source |
| xml |
an XmlDocument with request changes, its root element should be DAV:propertyupdate |
| cancellable |
optional Cancellable object, or null |
|
Whether succeeded. |