register
Description:
[ Version ( since = "1.0" ) ]
public async bool register (string network_id, Cancellable? cancellable) throws Error
  public async bool register (string network_id, Cancellable? cancellable) throws Error
Asynchronously requests registration with a given mobile network.
When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this
      method from. You can then call register.end to get the result of the operation.
See register_sync for the synchronous, blocking version of this method.
Parameters:
| this | 
           A Modem3gpp.  | 
      
| network_id | 
           The operator ID to register. An empty string can be used to register to the home network.  | 
      
| cancellable | 
           A Cancellable or   | 
      
| callback | 
           A TaskReadyCallback to call when the request is satisfied or   | 
      
| user_data | 
           User data to pass to   |