code: def test_output_tensor_error(self):
      a = np.random.rand(2, 3, 4)
      a_layer = DummyLayer()
      with self.assertRaisesRegex(
          ValueError, "operation outputs must be tensors."
      ):
          Node(a_layer, outputs=a, call_args=(), call_kwargs={})
  
file_path: keras/keras/ops/node_test.py
imports: import numpy
  from keras import Layer
  from keras import testing
  from keras.backend import KerasTensor
  from keras.ops.node import Node
label_desc: Use image node_id 3 for calling the NodeTest obj's underlying member method code with example usage: obj.test_output_tensor_error() without return types