connection
Description:
The connection of the account, or null if account is offline.
 Note that the returned Connection is not guaranteed to have any
      features pre-prepared (not even TP_CONNECTION_FEATURE_CORE) unless TP_ACCOUNT_FEATURE_CONNECTION has been prepared on
      the account
One can receive change notifications on this property by connecting to the notify
       signal and using this property as the signal detail. If TP_ACCOUNT_FEATURE_CONNECTION has been prepared, this signal will be
      delayed until the connection is ready.
This is not guaranteed to have been retrieved until 
        prepare_async has finished; until then, the value is null.