public VirtualGatewayPortMapping withProtocol(String protocol) {
        setProtocol(protocol);
        return this;
    }
<p>
The protocol used for the port mapping.
</p>

@param protocol
       The protocol used for the port mapping.
@return Returns a reference to this object so that method calls can be chained together.
@see VirtualGatewayPortProtocol
aws-java-sdk-appmesh/src/main/java/com/amazonaws/services/appmesh/model/VirtualGatewayPortMapping.java