code: def zone(self, name, dns_name=None, description=None):
          
          return ManagedZone(name, dns_name, client=self, description=description)
docs: Construct a zone bound to this client.
  
          :type name: str
          :param name: Name of the zone.
  
          :type dns_name: str
          :param dns_name:
              (Optional) DNS name of the zone.  If not passed, then calls to
              :meth:`zone.create` will fail.
  
          :type description: str
          :param description:
              (Optional) the description for the zone.  If not passed, defaults
              to the value of 'dns_name'.
  
          :rtype: :class:`google.cloud.dns.zone.ManagedZone`
          :returns: a new ``ManagedZone`` instance.