code: def setUp(self):
      self._adder = linear_operator_addition._AddAndReturnDiag()
  
imports: import numpy
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import linalg_ops
  from tensorflow.python.ops.linalg import linalg
  from tensorflow.python.ops.linalg import linear_operator_addition
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the AddAndReturnDiagTest obj's underlying member method code with example usage: obj.setUp() without return types