class_docstr: Most tests done in the base class LinearOperatorDerivedClassTest.
class_docstr_tok: ["Most","tests","done","in","the","base","class","LinearOperatorDerivedClassTest","."]
code: def test_zeros_matmul(self):
      operator1 = linalg_lib.LinearOperatorIdentity(num_rows=2)
      operator2 = linalg_lib.LinearOperatorZeros(num_rows=2)
      self.assertTrue(
          isinstance(
              operator1.matmul(operator2),
              linalg_lib.LinearOperatorZeros,
          )
      )
  
      self.assertTrue(
          isinstance(
              operator2.matmul(operator1),
              linalg_lib.LinearOperatorZeros,
          )
      )
  
imports: import numpy
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_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 21 for calling the LinearOperatorZerosTest obj's underlying member method code with example usage: obj.test_zeros_matmul() without return types