call_accept
Description:
Asynchronously invokes the Accept D-Bus method on this.
 When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this
      method from (see push_thread_default). You can then call 
      call_accept.end to get the result of the operation.
See call_accept_sync for the synchronous, blocking version of this method.
Parameters:
| this | |
| cancellable | A Cancellable or  | 
| callback | A TaskReadyCallback to call when the request is satisfied or  | 
| user_data | User data to pass to  |