A variadic argument list. The first argument (args[0]) is the optional
value parameter. Its presence is detected via args.length, allowing
the function to distinguish between an explicitly passed undefined value
and a completely omitted argument.
Whether the passed value features a custom applied type-identity.
Does approve whether the passed value features a custom applied type-identity, which is ... there are
Symbol.toStringTagrelated slots available, directly owned either by the passed value itself or by its prototype, and none of them can be matched against a built-in type-identity.