class_docstr: ADD Model
  
  Parameters
  ----------
   lr : float
       learning rate
   d_feat : int
       input dimensions for each time step
   metric : str
       the evaluation metric used in early stop
   optimizer : str
       optimizer name
   GPU : int
       the GPU ID used for training
code: def loss_pre_market(self, pred_market, label_market, record=None):
      pre_market_loss = F.cross_entropy(pred_market, label_market)
      if record is not None:
          record["pre_market_loss"] = pre_market_loss.item()
      return pre_market_loss
  
imports: from __future__ import division
  from __future__ import print_function
  import copy
  import math
  from typing import Text, Union
  import numpy
  import pandas
  import torch
  import torch.nn
  import torch.nn.functional
  import torch.optim
  from qlib.contrib.model.pytorch_gru import GRUModel
  from qlib.contrib.model.pytorch_lstm import LSTMModel
  from qlib.contrib.model.pytorch_utils import count_parameters
  from qlib.data.dataset import DatasetH
  from qlib.data.dataset.handler import DataHandlerLP
  from qlib.log import get_module_logger
  from qlib.model.base import Model
  from qlib.utils import get_or_create_path
  from torch.autograd import Function
label_desc: Use image node_id 4 for calling the ADD obj's underlying member method code with example usage: obj.loss_pre_market(pred_market, label_market, record) and returns: pre_market_loss