IO::Async::Resolver::DNS extends the IO::Async::Resolver class with extra
methods and resolver functions to perform DNS-specific resolver lookups. It does
not directly provide any methods or functions of its own.

These functions are provided for performing DNS-specific lookups, to obtain MX
or SRV records, for example. For regular name resolution, the usual getaddrinfo
and getnameinfo methods on the standard IO::Async::Resolver should be used.