Provide the ability to programmatically specify config sources for ReloadingCombinedConfigurationBuilder

I have the following configuration files:
prop_test1.xml
prop_test2.xml and so force.
There is one default file - default.xml.
And I have to combine prop_test1.xml with default.xml and get single combined configuration.
prop_test2.xml with default.xml and get another combined configuration.
With current solution I have to specify a configuration definition file for every pair. I think it will be nice to have the ability to programmatically specify files for ReloadingCombinedConfigurationBuilder.
Something like:
ReloadingCombinedConfigurationBuilder builder = new ReloadingCombinedConfigurationBuilder()
.configure(params.fileBased().addFile(new File("test1.xml").addFile(new File("default.xml")));