LinkGenerator and persistent parameters

Hi,
I have recently noticed, that LinkGenerator does not preserve persistent parameters when generating links, which I thought he is doing – $refUrl entering into the process of routing contains persistent parameters, but during constructing url they disappear.

Is this expected behaviour? I do understand, that LinkGenerator is typically used for generating link in email etc. where you typically don't want to pass current state of components, but in some cases I would like to have such behaviour – generate with keeping persistent parameters.

Thanks.