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.
code: def __init__(self, **kwargs):
      super().__init__(**kwargs)
      self.inputs = None
      self.outputs = None
      self._num_output_node = 1
  
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 1 to create a new Block object from inherited base classes: named_hypermodel with example: obj = Block()