class_docstr: Dataset class for quick embedding/label retrieval.
  Labels should be in the index space.
  
  If the labels provided are not in torch form, will convert them.
code: def __len__(self):
      return len(self.labels)
  
file_path: lightwood/lightwood/encoder/text/helpers/pretrained_helpers.py
imports: import torch
  from transformers import AdamW
label_desc: Use image node_id 3 for calling the TextEmbed obj's underlying member method code with example usage: obj.__len__() and returns: len