The class domainclassifer got two methods:
- domain() to extract all potential domains from a raw text
The method returns a list.
- validdomain() returning all the existing domains based on their
known DNS records sets like A,AAAA or CNAME records.
The method returns a set. If the extended option is requested, it's a list
of tuples containing the domain with their existing DNS records and
their returned data.