How to add custom settings in ElasticsearchSingleNodeTest unit tests

I've got a plug in service that inherits from AbstractLifecycleComponent that reads custom settings from the elasticsearch.yaml file.

How can I configure tests that inherit from ElasticsearchSingleNodeTest to use load my custom settings that the service needs instead of its default settings?

Or maybe there is a way to bind a Settings instance to my service that I populate manually just for my test?