    def get_output_dim(self) -> int:
        """
        Returns the dimension of the vector representing each token in the output of this
        `TextFieldEmbedder`.  This is _not_ the shape of the returned tensor, but the last element
        of that shape.
        """
        raise NotImplementedError
Returns the dimension of the vector representing each token in the output of this
`TextFieldEmbedder`.  This is _not_ the shape of the returned tensor, but the last element
of that shape.
allennlp/modules/text_field_embedders/text_field_embedder.py