answerSDP.swift

func answer(completion: @escaping (_ sdp: RTCSessionDescription) -> Void)  {
    let constrains = RTCMediaConstraints(mandatoryConstraints: self.mediaConstrains,
                                         optionalConstraints: nil)
    self.peerConnection!.answer(for: constrains) { (sdp, error) in
      guard let sdp = sdp else {
        return
      }
      
      self.peerConnection!.setLocalDescription(sdp, completionHandler: { (error) in
        completion(sdp)
      })
    }
  }