class_docstr: The base class for different Block.
  
  The Block can be connected together to build the search space for an
  AutoModel. Notably, many args in the __init__ function are defaults to be a
  tunable variable when not specified by the user.
docstr: Build the Block into a real Keras Model.
  
  The subclasses should override this function and return the output node.
  
  # Arguments
      hp: HyperParameters. The hyperparameters for building the model.
      inputs: A list of input node(s).
code: def build(self, hp, inputs=None):
      """Build the Block into a real Keras Model.
  
      The subclasses should override this function and return the output node.
  
      # Arguments
          hp: HyperParameters. The hyperparameters for building the model.
          inputs: A list of input node(s).
      """
      raise NotImplementedError
  
file_path: autokeras/autokeras/engine/block.py
imports: from tensorflow import nest
  from autokeras.engine import named_hypermodel
  from autokeras.engine import node
label_desc: Use image node_id 4 for calling the Block obj's underlying member method code with example usage: obj.build(hp, inputs) without return types