Proper use of linear module (not linear strategy)

The documentation for the ‘linear’ module is incomplete. It has no examples and no real explanation of the process flow. The explanation that it has does not make sense to me.
Can someone give me a good example of using the ‘linear’ module. Does it take a list of roles, or is it used like ‘block’ with a list of tasks, or something else?
Note, I am not talking about the linear strategy.

There is no module in Ansible called linear, only the strategy plugins has that name.

All modules in Ansible is listed here
https://docs.ansible.com/ansible/latest/modules/list_of_all_modules.html

A search in the source code
$ find git/ansible/ -iname '*linear*'
git/ansible/test/units/plugins/strategy/test_strategy_linear.py
git/ansible/test/integration/targets/strategy_linear
git/ansible/lib/ansible/plugins/strategy/linear.py

Just the linear strategy

Sorry, my mistake. Thanks.