// check if the state model definition exists and cache it
if (!_stateModelDefs.containsKey(stateModelId.stringify())) {
HelixDataAccessor accessor = _manager.getHelixDataAccessor();
Builder keyBuilder = accessor.keyBuilder();
StateModelDefinition stateModelDef =
accessor.getProperty(keyBuilder.stateModelDef(stateModelId.stringify()));
if (stateModelDef == null) {
throw new HelixException("fail to create msg-handler because stateModelDef for "
+ stateModelId + " does NOT exist");
}
_stateModelDefs.put(stateModelId.stringify(), stateModelDef);