code: def numericalize(self, batch, device=None):
      batch_char_ids = []
      for sentence in batch:
          sentence_char_ids = super().numericalize(
              sentence, device=device
          )
          batch_char_ids.append(sentence_char_ids)
      return torch.stack(batch_char_ids, dim=0)
  
file_path: pytext/pytext/fields/char_field.py
imports: import copy
  from collections import Counter
  from typing import List
  import torch
  from pytext.common.constants import VocabMeta
  from pytext.legacy import data, vocab
  from pytext.utils.data import no_tokenize
  from .field import VocabUsingField
label_desc: Use image node_id 4 for calling the CharFeatureField obj's underlying member method code with example usage: obj.numericalize(batch, device) and returns: torch