class_docstr: cross entropy loss for sequence to sequence 
code: def __init__(self, config):
      super().__init__(config)
  
imports: import delta.compat
  from delta.utils.loss.base_loss import Loss
  from delta.utils.loss.loss_utils import cross_entropy
  from delta.utils.loss.loss_utils import mask_sequence_loss
  from delta.utils.loss.loss_utils import ctc_lambda_loss
  from delta.utils.loss.loss_utils import crf_log_likelihood
  from delta.utils.loss.loss_utils import focal_loss
  from delta.utils.register import registers
label_desc: Use image node_id 1 to create a new SequenceCrossEntropyLoss object from inherited base classes: Loss with example: obj = SequenceCrossEntropyLoss(config)