class_docstr: Mixin abstract base class defining additional functionality required for neural network estimators. This base class
  has to be mixed in with class `BaseEstimator`.
class_docstr_tok: ["Mixin","abstract","base","class","defining","additional","functionality","required","for","neural","network","estimators",".","This","base","class","has","to","be","mixed","in","with","class","`","BaseEstimator","`","."]
docstr: :return: Boolean to indicate index of the color channels in the sample `x`.
code: def channels_first(self) -> bool:
      """
      :return: Boolean to indicate index of the color channels in the sample `x`.
      """
      return self._channels_first
  
imports: from abc import ABC, abstractmethod
  from typing import Any, Dict, List, Optional, Tuple, Union, TYPE_CHECKING
  import numpy
  from tqdm.auto import trange
  from art.config import ART_NUMPY_DTYPE
label_desc: Use image node_id 6 for calling the NeuralNetworkMixin obj's underlying member method code with example usage: obj.channels_first() and returns: self