code: def test_add_edge_cases():
      data = numpy.asarray([[1, 2, 3, 4]], dtype="f")
      with pytest.raises(TypeError):
          add()
      model = add(Linear(), Linear())
      model._layers = []
      Y, backprop = model(data, is_train=True)
      assert numpy.array_equal(data, Y)
      dX = backprop(Y)
      assert numpy.array_equal(dX, data)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_allclose
  from thinc.api import Dropout, Linear, Model, NumpyOps, add, clone, concatenate, map_list, noop
  from thinc.layers import chain, tuplify
label_desc: Use image node_id 35 for calling a global function with example usage: test_add_edge_cases() without return types