class_docstr: Block for image data.
  
  The image blocks is a block choosing from ResNetBlock, XceptionBlock,
  ConvBlock, which is controlled by a hyperparameter, 'block_type'.
  
  # Arguments
      block_type: String. 'resnet', 'xception', 'vanilla'. The type of Block
          to use. If unspecified, it will be tuned automatically.
      normalize: Boolean. Whether to channel-wise normalize the images.
          If unspecified, it will be tuned automatically.
      augment: Boolean. Whether to do image augmentation. If unspecified,
          it will be tuned automatically.
code: def build(self, hp, inputs=None):
      input_node = nest.flatten(inputs)[0]
      output_node = input_node
  
      if self.normalize is None and hp.Boolean(NORMALIZE):
          with hp.conditional_scope(NORMALIZE, [True]):
              output_node = preprocessing.Normalization().build(
                  hp, output_node
              )
      elif self.normalize:
          output_node = preprocessing.Normalization().build(
              hp, output_node
          )
  
      if self.augment is None and hp.Boolean(AUGMENT):
          with hp.conditional_scope(AUGMENT, [True]):
              output_node = preprocessing.ImageAugmentation().build(
                  hp, output_node
              )
      elif self.augment:
          output_node = preprocessing.ImageAugmentation().build(
              hp, output_node
          )
  
      if self.block_type is None:
          block_type = hp.Choice(
              BLOCK_TYPE, [RESNET, XCEPTION, VANILLA, EFFICIENT]
          )
          with hp.conditional_scope(BLOCK_TYPE, [block_type]):
              output_node = self._build_block(
                  hp, output_node, block_type
              )
      else:
          output_node = self._build_block(
              hp, output_node, self.block_type
          )
  
      return output_node
  
imports: from typing import Optional
  from tensorflow import nest
  from autokeras.blocks import basic
  from autokeras.blocks import preprocessing
  from autokeras.blocks import reduction
  from autokeras.engine import block
label_desc: Use image node_id 4 for calling the ImageBlock obj's underlying member method code with example usage: obj.build(hp, inputs) and returns: output_node