public Subscription withProtocol(String protocol) {
        setProtocol(protocol);
        return this;
    }
<p>
The subscription's protocol.
</p>

@param protocol
       The subscription's protocol.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-sns/src/main/java/com/amazonaws/services/sns/model/Subscription.java