public CaptionSource withKey(String key) {
        setKey(key);
        return this;
    }
<p>
The name of the sidecar caption file that you want Elastic Transcoder to include in the output file.
</p>

@param key
       The name of the sidecar caption file that you want Elastic Transcoder to include in the output file.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-elastictranscoder/src/main/java/com/amazonaws/services/elastictranscoder/model/CaptionSource.java