The file /usr/share/doc/nftables/examples/sysvinit/nftables.init is a typical
sysvinit script for you to use as /etc/init.d/nftables.

Given Debian default init system is systemd, I have no intention to support
sysvinit apart of providing this example file.

Read the script carefully before using it, as is just an example.
You will likely require to manually edit and install the script in order to
properly use it.

I will probably drop all sysvinit-related stuff like this in the future.
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		The nftables package Debian maintainer,
			Arturo Borrero Gonzalez - 12/Nov/2015