public GCMMessage withSound(String sound) {
        setSound(sound);
        return this;
    }
<p>
The sound to play when the recipient receives the push notification. You can use the default stream or specify
the file name of a sound resource that's bundled in your app. On an Android platform, the sound file must reside
in /res/raw/.
</p>

@param sound
       The sound to play when the recipient receives the push notification. You can use the default stream or
       specify the file name of a sound resource that's bundled in your app. On an Android platform, the sound
       file must reside in /res/raw/.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-pinpoint/src/main/java/com/amazonaws/services/pinpoint/model/GCMMessage.java