code: def test_graph_can_init_with_one_missing_output():
      input_node = ak.ImageInput()
      output_node = ak.ConvBlock()(input_node)
      output_node = ak.RegressionHead()(output_node)
      ak.ClassificationHead()(output_node)
  
      graph_module.Graph(input_node, output_node)
  
file_path: autokeras/autokeras/graph_test.py
imports: import os
  import keras_tuner
  import pytest
  import autokeras
  from autokeras import graph
label_desc: Use image node_id 10 for calling a global function with example usage: test_graph_can_init_with_one_missing_output() without return types