get_country_code

Queries the this's country calling code and optionally stores the country calling code's origin in source.

For instance when parsing "+1-617-5423789" this function would return one and assing E_PHONE_NUMBER_COUNTRY_FROM_FQTN to source.

Parameters:

this	the phone number to query
source	an optional location for storing the phone number's origin, or null

Returns:

A valid country calling code, or zero if no code is known.