class_docstr: Most tests done in the base class LinearOperatorDerivedClassTest.
code: def test_tape_safe(self):
      matrix = variables_module.Variable(
          [[3.0, 2.0, 0.0], [1.0, 6.0, 4.0], [0.0, 2, 2]]
      )
      operator = linalg_lib.LinearOperatorTridiag(
          matrix, diagonals_format="matrix"
      )
      self.check_tape_safe(operator)
  
imports: from tensorflow.python.framework import config
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import array_ops_stack
  from tensorflow.python.ops import gen_array_ops
  from tensorflow.python.ops import manip_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.ops.linalg import linalg
  from tensorflow.python.ops.linalg import linear_operator_test_util
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the LinearOperatorTriDiagMatrixTest obj's underlying member method code with example usage: obj.test_tape_safe() without return types