'Fetch a PhoneNumberInstance
:param unicode country_code: The country_code
:param unicode type: The type
:param unicode add_ons: The add_ons
:param dict add_ons_data: The add_ons_data
:returns: Fetched PhoneNumberInstance
:rtype: twilio.rest.lookups.v1.phone_number.PhoneNumberInstance'

def fetch(self, country_code=values.unset, type=values.unset, add_ons=values.unset, add_ons_data=values.unset):

    params = values.of({'CountryCode': country_code, 'Type': type, 'AddOns': add_ons})
    params.update(serialize.prefixed_collapsible_map(add_ons_data, 'AddOns'))
    payload = self._version.fetch('GET', self._uri, params=params)
    return PhoneNumberInstance(self._version, payload, phone_number=self._solution['phone_number'])
