class_docstr: A general neural network block when the input type is unknown.
  
  When the input type is unknown. The GeneralBlock would search in a large
  space for a good model.
  
  # Arguments
      name: String.
code: def build(self, hp, inputs=None):
      raise NotImplementedError
  
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 1 for calling the GeneralBlock obj's underlying member method code with example usage: obj.build(hp, inputs) without return types