I am trying to implement address_mapper.scan_build_files in v2 engine, during code browsing, I am wondering if it’s a good idea to move from "v2 engine backed LegacyBuildGraph" to "v2 engine backed LegacyAddressMapper"? it seems in v1 engine, most address related work (including scan_build_files and scan_addresses) is done through address_mapper. Currently in v2 engine, address_mapper does its work through LegacyBuildGraph (it has a reference to LBG). To implement scan_build_files in v2 address_mapper, I can do the same thing of course, but I feel it makes more sense to move scheduler and engine objects inside address_mapper.