Make LinearOperatorBlockDiag tape safety check different diagonal components.

PiperOrigin-RevId: 289172423
Change-Id: I337870843934bdfe2d49caf1977a2613560cb709
diff --git a/tensorflow/python/kernel_tests/linalg/linear_operator_block_diag_test.py b/tensorflow/python/kernel_tests/linalg/linear_operator_block_diag_test.py
index dc501b1..abaf9bf 100644
--- a/tensorflow/python/kernel_tests/linalg/linear_operator_block_diag_test.py
+++ b/tensorflow/python/kernel_tests/linalg/linear_operator_block_diag_test.py
@@ -213,20 +213,16 @@
     self.assertEqual(2, len(inverse.operators))
 
   def test_tape_safe(self):
-    matrix = variables_module.Variable([[1., 0.], [0., 1.]])
+    matrices = []
+    for _ in range(4):
+      matrices.append(variables_module.Variable(
+          linear_operator_test_util.random_positive_definite_matrix(
+              [2, 2], dtype=dtypes.float32, force_well_conditioned=True)))
+
     operator = block_diag.LinearOperatorBlockDiag(
-        [
-            linalg.LinearOperatorFullMatrix(
-                matrix,
-                is_self_adjoint=True,
-                is_positive_definite=True,
-            ),
-            linalg.LinearOperatorFullMatrix(
-                matrix,
-                is_self_adjoint=True,
-                is_positive_definite=True,
-            ),
-        ],
+        [linalg.LinearOperatorFullMatrix(
+            matrix, is_self_adjoint=True,
+            is_positive_definite=True) for matrix in matrices],
         is_self_adjoint=True,
         is_positive_definite=True,
     )