Requests the calendar backend to modify an existing object.
If the object does not exist on the calendar, an error will be returned.
For recurrent appointments, the mod argument specifies what to modify, if all instances (
ALL), a single instance (
THIS), or a specific set of instances (THIS_AND_PRIOR and
THIS_AND_FUTURE).
The call is finished by modify_object.end from the callback.
| this |
an Client |
| icalcomp |
Component to modify |
| mod |
Type of modification |
| opflags |
bit-or of OperationFlags |
| cancellable |
a Cancellable; can be null |
| callback |
callback to call when a result is ready |
| user_data |
user data for the |