def METHOD_NAME(self, xs, x_masks=None):
    """Inference duration.
    Args:
        xs (Tensor): Batch of input sequences (B, Tmax, idim).
        x_masks (ByteTensor, optional):
            Batch of masks indicating padded part (B, Tmax).
    Returns:
        LongTensor: Batch of predicted durations in linear domain (B, Tmax).
    """
    return self._forward(xs, x_masks, True)