Use of "extra" and "extra_vals"

[abhishek-ghose]

Hi,

I am trying to understand the role of setting the extra and extra_vals parameters in something like SRBFStrategy(). It seems like if I append the controller's fevalslist with appropriately populated EvalRecord objects (as shown in this example), the controller is able to leverage this prior information. What is purpose of also setting the extra, extra_vals parameters in SRBFStrategy()?

Regards