`(new type_is_recursive rec_flag tds)#go ()` returns whether `rec_flag, tds` is really a recursive type. We disregard recursive occurrences appearing in arrow types. You can override the search for certain type expressions by inheriting from this class.

inherit Ppxlib.Ast_traverse.iter
`val type_names : Ppxlib__.Import.string Ppxlib__.Import.list`
`method return_true : Ppxlib__.Import.unit ‑> Ppxlib__.Import.unit`
`method go : Ppxlib__.Import.unit ‑> Ppxlib__.Import.rec_flag`