hold method Null safety

Future<void> hold(
  1. SipHoldState direction
)

hold sip call direction : specify SipHoldState for direction of call flow

Implementation

Future<void> hold(
  SipHoldState direction,
) async {
  var payload = {"request": "hold", "direction": direction.name};
  JanusEvent response = JanusEvent.fromJson(await this.send(data: payload));
  JanusError.throwErrorFromEvent(response);
}