code: def test_update_signature():
      from cntk.layers.typing import Tensor
  
      input_dim = 14
  
      @C.Function
      def f(x):
          return x * x
  
      f.update_signature(Tensor[input_dim])
  
      assert f.outputs[0].shape == (input_dim,)
      assert f.x.shape == (input_dim,)
  
imports: import numpy
  import os
  import pytest
  import cntk
  from .ops_test_utils import compare_lists_of_np_arrays, AA, cntk_device
  from cntk.io import MinibatchSource, CTFDeserializer, StreamDefs, StreamDef
label_desc: Use image node_id 24 for calling a global function with example usage: test_update_signature() and returns: unknown