Get the files, this TargetRefs is referencing or producing, if any.
(targetRefs: StringAdd).self
(targetRefs: StringFormat).self
(targetRefs: ArrowAssoc[TargetRefs]).x
(Since version 2.10.0) Use leftOfArrow
instead
(targetRefs: Ensuring[TargetRefs]).x
(Since version 2.10.0) Use resultOfEnsuring
instead