Concepts
Providers
A Provider is an online service who makes temporary phone numbers available for use.
In Disposable Phonebook, Providers are represented by dedicated classes under dphonebook.lib.providers.
A provider class needs to inherit from dphonebook.lib.numberprovider.NumberProvider, and implement
the scrape method.
Writers
Writers are result-saving mechanism - where to put collected numbers? Writers are represented
by classes under dphonebook.lib.writer.
StdoutWriter-> print output to stdout consoleJsonWriter-> write output as JSON into a file. This output file can be fed into other tooling as data input.WebhookWriter-> POST results (in batches) to a HTTP endpoint