code: def testUnary(self):
      # Unary cases.
      self._check_gradient("->", ())
      self._check_gradient("aaa->a", (3, 3, 3))
      self._check_gradient("aabcd->ad", (3, 3, 5, 4, 4))
      self._check_gradient("aabcd->add", (3, 3, 5, 4, 4))
      self._check_gradient("abcd->da", (3, 5, 4, 2))
  
imports: import numpy
  from tensorflow.python.client import session
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_linalg_ops
  from tensorflow.python.ops import gradient_checker_v2
  from tensorflow.python.ops import special_math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import benchmark
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the EinsumGradTest obj's underlying member method code with example usage: obj.testUnary() without return types