docs: def split_qname(self, cybox_id):
          """
          Separate the namespace from the identifier in a qualified name and lookup the namespace URI associated
          with the given namespace.
          """
          if ':' in cybox_id:
              (namespace, uid) = cybox_id.split(':', 1)
          else:
              namespace = None
              uid = cybox_id
  
          if namespace and namespace in self.namespace_dict:
              namespace_uri = self.namespace_dict[namespace]
          else:
              logger.warning("Could not retrieve namespace for identifier %s" % (cybox_id))
              # TODO: Introduce configurable URI
              namespace_uri = None
  
          if not namespace_uri:
              if self.default_identifier_ns_uri:
                  namespace_uri = self.default_identifier_ns_uri
              else:
                  namespace_uri = "%s/%s" % (DINGOS_MISSING_ID_NAMESPACE_URI_PREFIX, namespace)
  
          return (namespace, namespace_uri, uid)