instance method sanitize_ips

# File actionpack/lib/action_dispatch/middleware/remote_ip.rb, line 184
      def sanitize_ips(ips) # :doc:
        ips.select! do |ip|
          # Only return IPs that are valid according to the IPAddr#new method.
          addr = IPAddr.new(ip)
          # We want to make sure nobody is sneaking a netmask in, which can only be
          # given after a slash.
          if ip.include?("/")
            range = addr.to_range
            next false unless range.begin == range.end
          end
          # Keep the parsed address for #first_non_proxy, by identity since the
          # same strings are checked there.
          (@parsed_ips ||= {}.compare_by_identity)[ip] = addr
          true
        rescue ArgumentError
          nil
        end
        ips
      end