code: def testPlaceholder(self):
      def check(equation, *input_and_placeholder_shapes):
          r = np.random.RandomState(0)
          inputs = []
          input_placeholders = []
          for (
              actual_shape,
              placeholder_shape,
          ) in input_and_placeholder_shapes:
              with self.subTest(
                  equation=equation,
                  actual_shape=actual_shape,
                  placeholder_shape=placeholder_shape,
              ):
                  input_np = np.array(r.randn(*actual_shape))
                  inputs.append(input_np)
                  input_placeholders.append(
                      array_ops.placeholder_with_default(
                          input_np, placeholder_shape
                      )
                  )
  
          a = np.einsum(equation, *inputs)
          b = self.evaluate(
              gen_linalg_ops.einsum(input_placeholders, equation)
          )
          self.assertAllClose(a, b, atol=1e-4, rtol=1e-4)
  
      check(
          "bijl,bjkm->bik",
          ((9, 2, 3, 5), (None, None, None, 5)),
          ((9, 3, 4, 7), (None, None, 4, None)),
      )
      check(
          "bijl,bjkm->bik", ((9, 2, 3, 5), None), ((9, 3, 4, 7), None)
      )
      check(
          "...ij,...->...i",
          ((4, 3, 1, 2), (None, 3, None, 2)),
          ((4, 3), (None, 3)),
      )
      check(
          "...ij,...jk->...ik",
          ((3, 1, 2, 3), None),
          ((1, 7, 3, 4), None),
      )
  
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 13 for calling the EinsumOpTest obj's underlying member method code with example usage: obj.testPlaceholder() without return types