Gets a timezone with given tzid, which had been previously put into the this with
put_timezone.
The returned ICalTimezone is owned by the this and should not be freed.
| this |
an CalCache |
| tzid |
a timezone ID to get |
| out_zone |
return location for the Timezone |
| cancellable |
optional Cancellable object, or null |
|
Whether succeeded. |