code: def test_grad_identity():
      # Check that the grad method of Identity correctly handles int dytpes
      x = theano.tensor.imatrix("x")
      # tensor_copy is Elemwise{Identity}
      y = theano.tensor.tensor_copy(x)
      l = y.sum(dtype=theano.config.floatX)
      theano.gradient.grad(l, x)
  
imports: from __future__ import absolute_import, print_function, division
  import unittest
  import numpy
  import theano
  from theano.gof import FunctionGraph
  from theano import gof
  from theano.tests import unittest_tools
  from theano.scalar.basic import floats, float16, float32, float64, ints, int8, int32, complex64, uint8, ComplexError, IntDiv, TrueDiv, Composite, add, div_proxy, and_, eq, neq, invert, mul, Scalar, InRange, cast, constant, switch
  from theano.scalar.basic import true_div, inv, log, log2, log10, log1p, exp, exp2, expm1, sqrt, deg2rad, rad2deg, cos, arccos, sin, arcsin, tan, arctan, arctan2, cosh, arccosh, sinh, arcsinh, tanh, arctanh
label_desc: Use image node_id 5 for calling a global function with example usage: test_grad_identity() without return types