wait_check_async
Description:
Combines wait_async with check_wait_status.
This is the asynchronous version of wait_check.
Parameters:
| this | |
| cancellable | 
           a Cancellable, or null  | 
      
| callback | 
           a TaskReadyCallback to call when the operation is complete  | 
      
| user_data | 
           user_data for   |