code: def test_elementwise_exceptions(self):
      with self.assertRaises(ValueError):
          not_callable_object = (1, 2, 3)
          layers.Elementwise(merge_function=not_callable_object)
  
      with self.assertRaises(ValueError):
          layers.Elementwise(merge_function="wrong-func-name")
  
      message = "expected multiple inputs"
      with self.assertRaisesRegexp(LayerConnectionError, message):
          layers.join(layers.Input(5), layers.Elementwise("multiply"))
  
      inputs = layers.parallel(
          layers.Input(2),
          layers.Input(1),
      )
      error_message = "layer have incompatible shapes"
      with self.assertRaisesRegexp(LayerConnectionError, error_message):
          layers.join(inputs, layers.Elementwise("add"))
  
file_path: neupy/tests/layers/test_merge.py
imports: import tensorflow
  import numpy
  from neupy import layers
  from neupy.utils import asfloat
  from neupy.exceptions import LayerConnectionError
  from base import BaseTestCase
label_desc: Use image node_id 2 for calling the ElementwiseTestCase obj's underlying member method code with example usage: obj.test_elementwise_exceptions() without return types