class PhysicalNetwork {

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof PhysicalNetwork) {
            final PhysicalNetwork that = (PhysicalNetwork) obj;
            return this.getClass() == that.getClass()
                    && Objects.equals(this.physicalNetwork,
                                      that.physicalNetwork);
        }
        return false;
    }

    private  PhysicalNetwork(String physicalNetwork);

}