docs: public void setDefault() {
          try {
              TelephonyManager telephonyManager = (TelephonyManager) getContext().getSystemService(Context.TELEPHONY_SERVICE);
              String phone = telephonyManager.getLine1Number();
              if (phone != null && !phone.isEmpty()) {
                  this.setNumber(phone);
              } else {
                  String iso = telephonyManager.getNetworkCountryIso();
                  setEmptyDefault(iso);
              }
          } catch (SecurityException e) {
              setEmptyDefault();
          }
      }