diff --git a/README.md b/README.md
index 2670c11a..2af52e99 100644
--- a/README.md
+++ b/README.md
@@ -199,6 +199,7 @@ Check out the **[contributing wiki](https://github.com/pion/webrtc/wiki/Contribu
 * [Kuzmin Vladimir](https://github.com/tekig)
 * [Alessandro Ros](https://github.com/aler9)
 * [Thomas Miller](https://github.com/tmiv)
+* [yoko(q191201771)](https://github.com/q191201771)
 
 ### License
 MIT License - see [LICENSE](LICENSE) for full text
diff --git a/examples/play-from-disk/main.go b/examples/play-from-disk/main.go
index a2eee908..b832cb7f 100644
--- a/examples/play-from-disk/main.go
+++ b/examples/play-from-disk/main.go
@@ -63,7 +63,7 @@ func main() {
 		if addTrackErr != nil {
 			panic(addTrackErr)
 		}
-		if _, addTrackErr = peerConnection.AddTrack(videoTrack); err != nil {
+		if _, addTrackErr = peerConnection.AddTrack(videoTrack); addTrackErr != nil {
 			panic(addTrackErr)
 		}
 
@@ -110,7 +110,7 @@ func main() {
 		if addTrackErr != nil {
 			panic(addTrackErr)
 		}
-		if _, addTrackErr = peerConnection.AddTrack(audioTrack); err != nil {
+		if _, addTrackErr = peerConnection.AddTrack(audioTrack); addTrackErr != nil {
 			panic(addTrackErr)
 		}
 
@@ -144,7 +144,7 @@ func main() {
 				}
 
 				// The amount of samples is the difference between the last and current timestamp
-				sampleCount := float64((pageHeader.GranulePosition - lastGranule))
+				sampleCount := float64(pageHeader.GranulePosition - lastGranule)
 				lastGranule = pageHeader.GranulePosition
 
 				if oggErr = audioTrack.WriteSample(media.Sample{Data: pageData, Samples: uint32(sampleCount)}); oggErr != nil {