if self.input_mode == "Dense":
            d[self.key_inputs] = DataDefinition([-1, -1, self.input_size], [torch.Tensor], "Batch of inputs, each being a sequence of items [BATCH_SIZE x SEQ_LEN x INPUT_SIZE]")
        elif self.input_mode == "Autoregression_First":
            d[self.key_inputs] = DataDefinition([-1, self.input_size], [torch.Tensor], "Batch of inputs, each being a single item [BATCH_SIZE x SEQ_LEN x INPUT_SIZE]")