code: def test_bad_layer(self):
      model = Sequential(name="seq")
      with self.assertRaisesRegex(ValueError, "Only instances of"):
          model.add({})
  
      model = Sequential(name="seq")
  
      class BadLayer(layers.Layer):
          def call(self, inputs, training):
              return inputs
  
      model.add(BadLayer())
      with self.assertRaisesRegex(
          ValueError, "can only have a single positional"
      ):
          model.build((None, 2))
  
imports: import numpy
  import pytest
  from keras import backend
  from keras import layers
  from keras import testing
  from keras.layers.core.input_layer import Input
  from keras.models.functional import Functional
  from keras.models.sequential import Sequential
label_desc: Use image node_id 10 for calling the SequentialTest obj's underlying member method code with example usage: obj.test_bad_layer() and returns: inputs