code: def test_with_flatten():
      model = with_flatten_v2(_memoize_input())
      Y, backprop = model(INPUT, is_train=True)
      assert Y == OUTPUT
      assert model.layers[0].attrs["last_input"] == INPUT_FLAT
      assert backprop(INPUT) == BACKPROP_OUTPUT
  
imports: from typing import List
  from thinc.api import Model, with_flatten_v2
label_desc: Use image node_id 3 for calling a global function with example usage: test_with_flatten() without return types