public PhysicalNetworkInterface withNetmask(String netmask) {
        setNetmask(netmask);
        return this;
    }
<p>
The netmask used to divide the IP address into subnets.
</p>

@param netmask
       The netmask used to divide the IP address into subnets.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-snowdevicemanagement/src/main/java/com/amazonaws/services/snowdevicemanagement/model/PhysicalNetworkInterface.java