KeyfileWriteHandler
Description:
[ Version ( since = "1.30" ) ]
public delegate bool KeyfileWriteHandler (Connection connection, KeyFile keyfile, KeyfileHandlerType handler_type, KeyfileHandlerData handler_data)
This is a hook to tweak the serialization.
Handler for certain properties or events that are not entirely contained within the keyfile or that might be serialized differently. The 
        type and handler_data arguments tell which kind of argument we have at hand.
Currently only the type nm_keyfile_handler_type_write_cert is supported.
The callee may call fail_with_error to abort the writing with error.
Parameters:
| connection | 
           the Connection that is currently written.  | 
      
| keyfile | 
           the KeyFile that is currently constructed.  | 
      
| handler_type | 
           the nmkeyfilehandlertype that indicates which type the request is.  | 
      
| handler_data | 
           the KeyfileHandlerData. What you can do with it  depends on the   | 
      
| user_data | 
           the user-data argument to keyfile_read.  | 
      
Returns:
| 
           the callee should return true if the event was handled. If the  event was unhandled, a default action 
            will be performed that depends on  the   |