Merge pull request #23 from amantoux/rtc_sender_add_streams

Add `addStreams` to `RTCRtpSender`

Author: cloudwebrtc

lib/src/rtc_rtp_sender_impl.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:html';
 import 'dart:js_util' as jsutil;
 
+import 'package:dart_webrtc/src/media_stream_impl.dart';
 import 'package:webrtc_interface/webrtc_interface.dart';
 
 import 'media_stream_track_impl.dart';
@@ -47,6 +48,17 @@ class RTCRtpSenderWeb extends RTCRtpSender {
     }
   }
 
+  @override
+  Future<void> setStreams(List<MediaStream> streams) async {
+    try {
+      final nativeStreams = streams as List<MediaStreamWeb>;
+      jsutil.callMethod(_jsRtpSender, 'setStreams',
+          nativeStreams.map((e) => e.jsStream).toList());
+    } on Exception catch (e) {
+      throw 'Unable to RTCRtpSender::setStreams: ${e.toString()}';
+    }
+  }
+
   @override
   RTCRtpParameters get parameters {
     var parameters = jsutil.callMethod(_jsRtpSender, 'getParameters', []);