def _calc_logits(self, X):
return self.forward(X)<EOL>
Calculate the logits.

:param X: The input (batch) of the model contains word sequences for lstm
    and features.
:type X: For word sequences: a list of torch.Tensor pair (word sequence
    and word mask) of shape (batch_size, sequence_length).
    For features: torch.Tensor of shape (batch_size, feature_size).
:return: The output logits of model.
:rtype: torch.Tensor of shape (batch_size, num_classes)