Uses a model getRefId() method whenever possible to get a reference ID.
If the model does not have an implementation of that method it returns undefined.
If the model has an implementation, but that implementation returns anything other than
a string it will throw.
Uses a model
getRefId()method whenever possible to get a reference ID. If the model does not have an implementation of that method it returnsundefined. If the model has an implementation, but that implementation returns anything other than astringit will throw.