     
 }
 
-public class BasicMediaStream: MediaStream {
+class BasicMediaStream: MediaStream {
     
-    public var streamId: String = ""
-    public var videoTrackId: String = ""
-    public var audioTrackId: String = ""
-    public var creationTime: Date
+    var streamId: String = ""
+    var videoTrackId: String = ""
+    var audioTrackId: String = ""
+    var creationTime: Date
     
-    public var videoCapturer: VideoCapturer? {
+    var videoCapturer: VideoCapturer? {
         willSet {
             if var oldValue = videoCapturer {
                 // Do not autostop here, let others manage videoCapturer's life cycle

        }
    }
    
    public var nativeStream: RTCMediaStream
    
    public var nativeVideoTrack: RTCVideoTrack? {
        get { return nativeStream.videoTracks.first }
    }
    
    public var nativeVideoSource: RTCVideoSource? {
        get { return nativeVideoTrack?.source }
    }
    
    public init(nativeStream: RTCMediaStream) {
        self.nativeStream = nativeStream
        streamId = nativeStream.streamId
        creationTime = Date()
    }
    
    private static let dummyCapturer: RTCVideoCapturer = RTCVideoCapturer()
    public func render(videoFrame: VideoFrame?) {
        if let frame = videoFrame {
            // フィルターを通す
            let frame = videoFilter?.filter(videoFrame: frame) ?? frame

        }
    }
    
    var videoFilter: VideoFilter?
    
    var videoRenderer: VideoRenderer? {
        get {
            return videoRendererAdapter?.videoRenderer
        }
