docstr: The size of one token.
code: def d_token(self) -> int:
      """The size of one token."""
      y = self.forward(torch.ones(1, self.in_features))
      return y.shape[-1]
  
imports: from typing import List, Optional
  import torch
  from torch import Tensor, nn
  from ..constants import CATEGORICAL, FEATURES, LABEL, LOGITS, NUMERICAL
  from .custom_transformer import CLSToken, Custom_Transformer, _TokenInitialization
  from .utils import init_weights
label_desc: Use image node_id 3 for calling the NumEmbeddings obj's underlying member method code with example usage: obj.d_token() and returns: y