BertTextClassifier __init__ guaranteed to raise NotImplementedError

https://github.com/allenai/scibert/blob/ae9f98f58a9793781148ccf715b03f7160060f24/scibert/models/bert_text_classifier.py#L37

BertTextClassifier requires an instance of TextFieldEmbedder and calls `get_output_dim` on that instance, however that method always raises NotImplementedError. Is this meant to deliberately un-implement a method from the superclass, or is it intended that that functionality will be implemented at a future time?