onProceeding method
Handle 1xx response event raised by library and route it to matched call instance
Implementation
void onProceeding(int callId, String response) {
_logs?.print('onProceeding callId:$callId response:$response');
int index = _callItems.indexWhere((c) => c.myCallId==callId);
if(index != -1) _callItems[index].onProceeding(response);
}