def modify_customer(self, handle, address, phone, email=None, vat=None, fax=None,
                        company_name=None, additional_data=None, extension_additional_data=None):
        """Modify a customer."""

        self.request(E.modifyCustomerRequest(
            E.handle(handle),
            E.vat(vat or ''),
            _get_phone_xml('phone', phone),
            _get_phone_xml('fax', fax),
            E.address(
                E.street(address.street),
                E.number(address.number),
                E.suffix(address.suffix or ''),
                E.zipcode(address.zipcode),
                E.city(address.city),
                E.state(address.state or ''),
                E.country(address.country),
            ),
            E.email(email or ''),
            _additional_data(additional_data),
            _extension_additional_data(extension_additional_data),
        ))

        return True
Modify a customer.