class_docstr: MLP for categorical input. The input dimension is automatically computed based on
  the number of categories in each categorical column.
code: def input_keys(self):
      return [self.categorical_key]
  
file_path: autogluon/multimodal/src/autogluon/multimodal/models/categorical_mlp.py
imports: from typing import List, Optional
  import torch
  from torch import nn
  from ..constants import CATEGORICAL, FEATURES, LABEL, LOGITS
  from .mlp import MLP
  from .utils import init_weights
label_desc: Use image node_id 3 for calling the CategoricalMLP obj's underlying member method code with example usage: obj.input_keys() and returns: list