code: def encode(self, labels):
      if type(labels) == list:
          return [self.encode(label) for label in labels]
      label = labels  # label is a string
      if label not in self.label2index:
          index = self.vocab_size
          self.label2index[label] = index
          self.index2label[index] = label
          self.vocab_size += 1
          return index
      else:
          return self.label2index[label]
  
imports: import logging
  from os.path import join
  import pytorch_lightning
  from pytorch_lightning.loggers import WandbLogger
  from torch.optim import AdamW
  import torch.nn
  import torch
  from torchmetrics import F1
  from torch.utils.data import DataLoader, Dataset
  from transformers import AutoTokenizer, AutoModel
label_desc: Use image node_id 2 for calling the LabelEncoder obj's underlying member method code with example usage: obj.encode(labels) and returns: unknown, index, self