class_docstr: Flatten the input tensor with Keras Flatten layer.
class_docstr_tok: ["Flatten","the","input","tensor","with","Keras","Flatten","layer","."]
code: def build(self, hp, inputs=None):
      inputs = nest.flatten(inputs)
      utils.validate_num_inputs(inputs, 1)
      input_node = inputs[0]
      if len(input_node.shape) > 2:
          return layers.Flatten()(input_node)
      return input_node
  
imports: from typing import Optional
  import tensorflow
  from tensorflow import nest
  from tensorflow.keras import layers
  from autokeras.engine import block
  from autokeras.utils import layer_utils
  from autokeras.utils import utils
label_desc: Use image node_id 1 for calling the Flatten obj's underlying member method code with example usage: obj.build(hp, inputs) and returns: input_node, layers