public TunnelOption withPreSharedKey(String preSharedKey) {
        setPreSharedKey(preSharedKey);
        return this;
    }
<p>
The pre-shared key (PSK) to establish initial authentication between the virtual private gateway and the customer
gateway.
</p>

@param preSharedKey
       The pre-shared key (PSK) to establish initial authentication between the virtual private gateway and the
       customer gateway.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/TunnelOption.java