def validate_address!(addr)
      ip = IPAddr.new(addr)

      unless ip.ipv4?
        raise NotImplementedError, 'Only IPv4 is supported by this library'
      end

      if addr.include?('/')
        raise ArgumentError, 'Please specify a host IP address (without mask)'
      end

      addr.to_s
    end
def validate_address!(addr)
      ip = IPAddr.new(addr)

      unless ip.ipv4?
        raise NotImplementedError, 'Only IPv4 is supported by this library'
      end

      if addr.include?('/')
        raise ArgumentError, 'Please specify a host IP address (without mask)'
      end

      addr.to_s
    end
Validate that the given string is a valid IP address.

 @raises ArgumentError, NotImplementedError